The visitors opened the scoring early on, as Roman Kienast fired in the Austrian champions' first goal of the tournament from 20 yards out.
Read how all the action unfolded below:
6.47pmGood evening! It's just under an hour until kickoff at the Estadio do Dragao, where both sides will be looking to keep their chances of reaching the knockout stages alive. The clubs have already announced their team news, let's take a look at the lineups...
6.49pmPORTO STARTING XI: Helton, Danilo, Maicon, Mangala, Sandro, Gonzalez, Josue, Lica, Fernando, Defour, Martinez
6.51pmAUSTRIA VIENNA STARTING XI: Lindner, Rogulj, Ortlechner, Suttnerr, Koch, Holland, Dilaver, Royer, Hosiner, Murg, Kienast
6.53pmPORTO SUBSTITUTES: Fabiano, Reyes, Otamendi, Herrera, Quintero, Varela
6.55pmAUSTRIA VIENNA SUBSTITUTES: Kardum, Ramsebner, Leovac, Simkovic, Mader, Okotie
6.59pmAustria Vienna can still reach the knockout stages, despite not having won a game so far, but they need to win both of their remaining group fixtures, and hope other results go their way. Porto go into this game sitting third, but are just two points behind second-placed Zenit St Petersburg.
7.02pmAhead of this evening's match, Porto coach Paulo Fonseca told reporters: "Porto go into every match wanting to win and it is imperative we do so. At the moment things are quite clear; if we want to think about qualifying for the next round we have to win the game with Austria Vienna. We had trouble beating this same opponent in Austria. They are a team on the up, with three wins in their last three league games, and who defend well. But we have an obligation to win here and we are motivated."
7.05pmAustria coach Nenad Bjelica said at his pre-match press conference: "We have talked about our form a lot within the squad and a crisis always gives you the chance to improve things, I think we have become a lot stronger."
7.08pmBoth teams head into tonight's game in strong domestic form. The visitors have won their last three Austrian Bundesliga matches, partially down to the goals on in-form striker Philipp Hosiner, who scored a hat-trick during their 5-0 demolition of Wacker Innsbruck at the weekend.
7.12pmPorto top the Primeira Liga and are unbeaten in their first 10 league games this season. They made a strong start to their Champions League campaign, beating tonight's opponents in their opening group game encounter, but have been unable to match their domestic form, losing to group leaders Atletico Madrid, before losing and drawing with Zenit.
7.16pmSpeaking of the other clubs in group G, Zenit and Atletico have already finished their match this evening, sharing a 1-1 draw. The Spanish side were already sure of their place in the knockout stages, but gaining a point puts pressure on Porto this evening. If tonight's hosts fail to win tonight, they'll have to beat the Madrid side in their final game of the campaign, and hope Austria can get a result against Zenit.
7.20pmAustria and Porto have played on three previous occasions, with the Vienna side yet to score a point against tonight's opponents. One of those previous meetings was in the 2002-03 UEFA CUP, which Porto went on to win during Jose Mourinho's time in charge of the club.
7.25pmAs well as this game, you can follow all of tonight's Champions League matches with Sports Mole this evening, with three of the five British clubs in the tournament in action today.
7.29pmAs I mentioned earlier, Austria are still looking for their first win of the campaign, they're also after their opening goal! Only twice in the history of the tournament has a club finished the group stage without finding the back of the net.
7.34pmOf course, Porto are previous winners of this competition. Austria do not have such a prolific history in European competition, but they have been regulars in Europe since the 1960s, reaching the semi-finals of the Europeans Cup in their 1978-89, and the same stage in the UEFA Cup Winners' Cup in the 82-83 season.
7.39pmPREDICTION! With the players due to head out to the pitch in the next couple of minutes, it's time for a quick prediction. While Austria need the win to keep their place in the competition, I can't see it happening tonight. I'm going for a 2-0 home win.
7.42pmThe players are just coming out of the tunnel ready for tonight's match. Worryingly for the visitors, it's 12 years since an Austrian side won a Champions League game beyond the qualifying rounds.
1 minAustria get the game underway.
3 minA nervy opening couple of minutes for both teams. Austria try to push up the pitch from the kickoff, but are quickly forced back before Lindner has to launch it forward. Porto manage to break into the Austria box with a quick burst from midfield, but Lica's effort gets deflected behind for a corner.
5 minCHANCE! From the corner, Jackson Martinez finds himself unmarked and goes up for the header, but his effort is off-target. The home side quickly get the ball back though, and a bearing down on the Austria penalty area again.
7 minJames Holland makes a run for the visitors, but his attempted pass for Hosiner is easily intercepted by Sandro. Incidentally, the left-back would miss the final group stage game if he were to pick up a booking this evening. Hosiner is in the same position for Austria.
8 minCHANCE! Lica is on the ball again for the hosts and puts in a strong cross from out wide, but Lindner is able to claim it before any of Lica's teammates can get to it.
10 minBoth teams are giving away possession quite easily at the moment. Lica steals it away from Dilaver in midfield, but loses out when trying to pull the ball back for Sandro. The defender tries to take on Koch to win it back, but Austria get the ball clear.
11 minGOAL! Porto 0-1 Austria Vienna (Kienast)
11 minAustria Vienna have their first goal of the campaign, and what a finish it is by Roman Kienast! The midfielder lashes the ball in from the edge of the box with the visitors' first effort of the game. In truth, Danilo should have done better for Porto, having given Keinast too much time and space.
14 minCHANCES! Porto have a chance for a quick equaliser but Lindner manages to tip the strikers acrobatic effort wide. Austria pounce on the counter-attack, with Hosiner lining up a strike, but Lucho Gonzalez manages to get a tackle in at the last second to put it behind for a corner.
18 minPorto are starting to dominate the possession but haven't created a decent chance since Lindner's save. Lica is continuing to test the Austria defenders, having shown impressive pace early in this game, but with just the one recognised striker on the pitch, the hosts are struggling to get support in the box.
22 minCHANCE! Josue makes a move forward and looks to set up Lucho Gonzalez, but the midfielder take a step too far, and Lindner gets time to make himself big, and manages to get a hand to the ball.
25 minPENALTY APPEAL! Austria manage to get the ball down the other end, and think that they should have had a penalty after Danilo appeared to knock the ball away with his arm. It didn't look like a deliberate hand ball, but I've seen penalties given for that kind of contact before. That may have been a lucky escape for Porto.
29 minAfter a rather eventful 15-minute spell, it's fallen a little flat, with both sides struggling to keep possession again. However, Porto manage to win a free kick in a dangerous position as Lica is dragged down by Suttner.
32 minCHANCE! From the free kick, the ball falls to Martinez in the penalty area, but Lica is judged to be offside before the striker can get the shot away. The chance does seem to have lifted the home side though, as they're quickly on the attack again and have another corner.
34 minCHANCE! Maicon gets a chance to head in the equaliser from the corner for Porto, but he doesn't get enough power behind the ball, allowing Lindner to make an easy save. The Austria goalkeeper has made some crucial stops so far in this match.
36 minAustria have been enjoying a couple of minutes of possession. Despite being a goal ahead, they've only had the odd spell on the ball in this opening half. However, Porto win the ball back when Murg's delivery for Hosiner is blocked by Gonzalez.
37 minCHANCE! Once again, Martinez is denied by a solid save from Lindner following a quick break through midfield. The Porto striker will be disappointed not to have scored at least once in this opening half.
41 minLica sends a long ball in looking for Martinez again, but some good marking from Ortlechner ensures that the ball goes behind for a corner, which is swiftly dealt with by the visitors. Porto have had plenty of corners in this first half, but have rarely tested Lindner from them.
44 minPorto are really trying to run at the Austria goal in the final minutes of this first half as they try to level before the break, but Holland holds up Martinez to get the ball back to Lindner. Austria manage to break from the keeper's throw and win a corner at the other end, but Helton is able to claim it.
45 minHALF TIME: Porto 0-1 Austria Vienna
8.31pmThe half-time whistle is met with a chorus of boos from the Porto fans. They're clearly unhappy with the half-time score, which sees the hosts trail for Group G's bottom side thanks to an 11th-minute rocket from Roman Kienast, which was Austria Vienna's first goal of the tournament this season.
8.35pmWhen you look at the stats from the first half, it's easy to see why the home supporters aren't too pleased. Porto had 12 shots, with five on target, while Austria had just one, which resulted in the goal. The hosts also had eight corner compared to the visitors' two and 64% of the possession.
8.38pmHeinza Lindner's performance in the Austria goal has been impressive. He's made five saves and claimed the ball from a couple of crosses to frustrate Porto. Jackson Martinez has kept him busy, with the striker proving a threat in the air in the first half, but he hasn't been able to get the better of the impressive goalkeeper yet.
8.42pmIf Porto do lose tonight, it will make for a fascinating final round of games in Group G. Avoiding defeat tonight would ensure that the Portuguese champions are at least in the Europa League, but an Austria win means they could progress with a win over Zenit in their next game. Porto still have to face group leaders Atletico Madrid.
8.44pmThe players are heading back out for the second half, and it looks like Porto will be making a change, with Varela warming up.
8.45pmSUB! Silvestre Varela does indeed come on, replacing Steven Defour, who didn't really have much of an impact in the opening 45 minutes.
46 minPorto get the game back underway.
48 minPorto seem to have a bit of urgency about them in the opening couple of minutes of the second half, immediately pressing towards the Austria goal. Sandro delivers a high ball in, and it's put behind for a corner.
49 minGOAL! Porto 1-1 Austria Vienna (Martinez)
49 minHaving done so well in the first half, Lindner finds himself in no-man's land from the corner. Mangala is the first to get the ball, drawing the keeper off his line, but the defender heads it on to Jackson Martinez, who heads in the equaliser.
51 minPorto also get the chance to make it 2-1 straight away as Josue makes a superb run from midfield, but his ball into the box is punched away by Lindner.
54 minAustria have upped the tempo as they try to get back in front, but Josue manages to steal the ball away from the visitors and charges towards the Porto goal before picking out Varela, who passes to Danilo, but his long-range shot goes wide.
55 minBOOKING! Suttner picks up the first yellow card of the game for a wild challenge on Varela.
56 minCHANCE! Porto have a free kick from a strong position following Suttner's foul, and it allows Sandro to have a shot at goal. Moments later Lucho Gonzalez control the ball with his chest before lashing it towards goal, but the Austria keeper continues to look strong.
60 minCHANCE! Austria manage to create a couple of half-chances on the break, as Hosiner blasts in a low effort which goes just wide of the Porto goal, before a Royer effort is blocked by Maicon.
64 minCHANCE Several Porto players have shots blocked in a promising looking move by the hots. Varela appears to have the last touch, but his effort is deflected behind for a corner. Jackson and Lica were among those who also had efforts, but Austria had plenty of men back to get the blocks in.
64 minSUB! Marin Leovac comes off the bench for the visitors, replacing Thomas Murg.
65 minSUB! It's an attack-minded change for the hosts, as Lica makes way for 20-year-old striker Ricardo Pereira, who makes his first appearance in the Champions League.
68 minPorto are really pressing for a winner as they are awarded yet another corner, but Varela is penalised for a clumsy hold on Suttner. Austria are really having to be alert at the back at the minute though.
69 minCHANCE! Martinez fires the ball in from out wide in the direction of Gonzalez, who manages to get the shot away, but some close marking forces him to make a mistake, and it goes wide.
70 minSUB! It's a second change for the visitors, with Florian Mader coming on for Emir Dilaver in what should be pretty much a straight swap.
71 minAustria win a free kick after Mader is on the receiving end of a hard challenge from Jackson Martinez, but they can't find the target from the delivery.
72 minSUB! The home side make their final change as Josue, who has had a heavy workload this evening, makes way for Juan Quintero.
75 minAustria are managing to force Porto back away from their goal, but they can't string enough passes together to create a threat of their own. Martinez tries to set up Gonzalez for Porto, but the midfielder can't turn to the goal in time.
78 minMartinez looks for his teammates again, having dropped back into a more creative midfield role as this half as progressed. This time he finds Varela on the edge of the box, but the midfielder is swamped by Austria defenders and forced away from the penalty area.
81 minPorto win another corner which Quintero whips in, but it's swiftly cleared by the visitors. Austria's defending has been resolute while the hosts have been pushing for the winning goal, but they haven't provided much threat up front.
82 minSUB! Austria know that they need a win, and with that it mind they take off defender Markus Suttner, and bring on striker Rubin Okotie.
83 minCHANCE! Porto come within inches of taking the lead as Martinez climbs up high for a header, but Mangala goes for the same ball, and accidentally deflects the striker's effort behind.
87 minYet again, Porto have a corner, but Rogulj heads the initial danger away. Maicon looks to force it back in for the home side, before Danilo sends in a cross for Quintero, but the midfielder his half a step too late getting to the ball, allowing Ortlechner to clear.
89 minAustria look like they're on the move as Royer makes a brilliant run from the back, but leaves it too late as he looks for support in the box, as Maicon is able to make the block.
90+1 minBOOKING! Kaja Rogulj is shown a yellow card for dragging down Martinez by his shirt. From the resulting free kick, Quintera goes straight for goal from 30 yards out, giving Lindner as easy save. It's a waste, as he had six teammates in the box.
90+2 minCHANCE! It's a golden opportunity for Jackson Martinez as he gets the ball open in the box, but he taps his shot straight to the Austria keeper. Porto will be questioning what exactly they have to do to get a second goal.
90+3 minBOOKING! Leovac is shown the yellow for a late tackle in Quintero, giving the home side a free kick with the last move of the game, but it's cleared. That should be all we have time for...
90+3 minFULL TIME: Porto 1-1 Austria Vienna
9.36pmIt's the result that doesn't really do either side any favours. THe draw ensures that Austria Vienna will finish bottom in Group G, ending their European involvement for another season. Meanwhile, Porto know that they need a win, and a favour from tonight's opponents in the last round of fixtures to progress in this tournament. The silver lining is that they're guaranteed at least a spot in the Europa League.
9.38pmPorto will be left scratching their heads as to how they managed not to add a second goal. The home side had 26 shots, nine on target and 68% of the possession over the 90 minutes.
9.41pmWell that's all from this match, but stick around for reports and reaction to all of this evening's Champions League matches, and join us again tomorrow night, when Manchester United, Manchester City and Real Madrid will all be in action in Europe's premier club competition. Until then, thanks for joining me this evening, goodbye.