The defending champions were ahead early on because of a defensive mistake from the Azzuri, and led 17-3 at the break.
Read how all the action unfolded below:
2.02pmGood afternoon! It's around half-an-hour until kickoff at the Millennium Stadium, where Wales begin the defence of their Six Nations title against the tournament's lowest-ranked side, Italy. Let's start with a look at the team's for this afternoon's match...
2.04pmWALES STARTING XV: Halfpenny, Cuthbert, Williams, Roberts, North, Priestland, Phillips, James, Hibbard, Adam Jones, Charteris, Alun Wyn Jones, Lydiate, Tipuric, Faletau
2.06pmITALY STARTING XV: McLean, Esposito, Campagnaro, Sgarbi, Sarto, Allan, Gori, Rizzo, Rhiraldini, Castrogiovanni, Geldenhuys, Bortolame, Zanno, Bergamasco, Parisse
2.09pmFor the home side, Justin Tipuric gets the nod ahead of Sam Warburton, who is named among today's replacements, leaving Alun Wyn Jones to take the captain's armband.
2.11pmSergio Parisse captains the visitors. The Argentine-born number eight missed last year's encounter with the Welsh side after receiving a red card while on duty with Stade Francais.
2.14pmThe coin toss for this afternoon's match took place a short time ago. Italy won and chose to kick, so they'll be starting with the ball. Meanwhile, it's worth noting that the roof at the Millennium Stadium will be closed this afternoon, which should help create quite an atmosphere.
2.17pmAhead of this afternoon's match, Warburton told reporters: "Within the group there is real motivation to make it three titles in a row and make history. That's our only focus now."
2.20pmIn their 14 previous Six Nations campaign, Italy have secured the wooden spoon on nine occasions! However, they've claimed wins against every team in the competition except England. Their only away win came in 2007, when they defeated Scotland at Murrayfield.
2.22pmAs well as coverage of this game, we'll have live commentaries from the other two matches taking place this weekend. England get their campaign underway later with a visit to France, while Scotland take on Ireland tomorrow.
2.24pmThe players have just made their way out ready for kickoff. We're not ready to get underway yet though, as the anthems for both countries will be played before kickoff.
2.27pmPREDICTION! With kickoff just a couple of minutes away it's time to make a prediction. Wales are obviously the favourites for this competition, they have the stronger squad and home advantage, while the Italians have bought an inexperienced bench. I can see Wales winning by 10 points this afternoon.
2.30pmREFEREE WATCH! Ireland's John Lacey takes charge of this afternoon's game, while Scottish official Iain Ramage will be in charge of the TV reviews. Glen Jackson of New Zealand and Francisco Pastrana from Argentina are the touch judges.
1 minKICKOFF! Italy get the game underway.
3 minMcLean brings the ball out from the back for Italy before offloading to Castogiovanni, who moves the ball into Wales territory. It's sounds like quite a few Italian fans are in the stadium as there's a huge roar as he carries the ball. However, the move comes to an end when Faletau wins a penalty for Wales, giving the home side a lineout at the half-way line.
4 minTRY! Wales 5-0 Italy (Cuthbert)
4 minIt's a dreadful mistake from Angelo Esposito to allow Alex Cuthbert in for Wales. Priestland chips the ball forward looking for Cuthbert, but it looks like Esposito will claim it for Italy. However, the debutante allows the ball to slip through his hands, and all Cuthbert has to do is pick it up. That's the easiest try he'll score all tournament!
5 minCONVERSION! Wales 7-0 Italy (Halfpenny)
8 minWales are almost in again as George North gets the ball out wide. However, he tries to chip it forward for a group of his teammates all sprinting towards the try line, but the Italian manage to guide it into touch. Wales have the scrum, with a knock-on quickly hands possession back to Italy.
11 minItaly take two attempts at getting their scrum underway, but Wales are twice penalised for collapsing the scrum, and the referee gives up, awarding the visitors the penalty. It's kicked just short of the half-way line by McLean to give the Azzuri lineout.
13 minA well-taken lineout finds Bergamasco but he's fouled by Lydiate, giving the visitors a chance to get their first points on the board with a short penalty.
14 minPENALTY! Wales 7-3 Italy (Allan)
14 minTommaso Allan easily splits the upright from straight in front of the posts to leave Italy just four points down.
16 minOn the restart, Faletau offloads the ball to Hibbard, who barges his way through the Italian forwards, but the visitors get the ball back when Parisse tackles Phillips, forcing the ball loose. Italy also pick up a penalty, and have the lineout inside Wales territory.
19 minGeorge North ends up with the ball after throw for the Italy lineout fails to find an Azzuri player, but he can't spot a gap through the Italy line, and Wales end up having to kick. However, Scott Williams takes a big hit from Campagnaro, allowing the home side to kick down field for a lineout from a strong position.
21 minNorth shows his dangerous pace with a burst out wide before looking for Alun Wyn Jones outside, but he doesn't have the same pace as North, and is easily stopped by Campagnaro just a couple of metres short of the try line.
24 minItaly have defending well so far in this match, dictating the pace of the game and restricting the potentially destructive Wales attack to just the one try. However, they've not really threatened that much while in Wales territory. That said, the Azzuri are probably still the happier of the two sides at the moment.
27 minItaly force Wales back to their own try line with some physical play. Priestland tries to kick the ball clear, but is almost chased down, only just getting the ball away. Italy try to maintain the pressure, but Sarto is penalised for offside.
29 minPENALTY! Wales 10-3 Italy (Halfpenny)
29 minBergamasco gives away the penalty for taking out an opponent during a Wales lineout. It's a tricky angle for Halfpenny, and he does appear to slip during his run up, but he's still able to squeeze it inside the right upright to restore Wales's lead to seven.
32 minWales are on the attack straight from the restart with Alex Cuthbert dashing the right touchline. Wales win the scrum deep in Italy territory, but the visitors win a penalty when Hibbard is caught holding on.
34 minParisse tries to launch Italy down the other end, but loses out to Charteris, but the Azzuri get the ball back when the hosts knock on.
36 minNO TRY! Parisse and Jamie Roberts both battle for the ball just short of the Wales try line as McLean kicks it downfield looking for his captain. Parisse manages to collect it and dashes over the try line, but he doesn't celebrate. It's immediately clear why when looking at the replays, he actually got his hands to it first and knocks it forward, so Wales will have the scrum.
38 minTRY! Wales 15-3 Italy (Williams)
38 minFrom a lineout just inside Italy territory, Jamie Robert dashes towards the try line, but he can see he's going to get tackled short, so tosses it to his left for Scott Williams, who has plenty of space in front of him to add Wales's second try of the game.
39 minCONVERSION! Wales 17-3 Italy (Halfpenny)
40 minItaly try a last-gasp effort to get their opening try with the last move of the half, as McLean kicks it deep, but Priestland takes it into touch for Wales as the siren sounds for the end of the opening half.
40 minHALF TIME: Wales 17-3 Italy
3.17pmFirst-half tries from Alex Cuthbert and Scott Williams have left Wales with a commanding lead at half time. In truth, it's a bit flattering for the hosts. Italy defended superbly for much of the opening 40 minutes, but were undone by a horrendous Angelo Esposito error early on, and a superb run from Jamie Robert to set up the second.
3.20pmWales had slightly more possession that their opponents in the first half, claiming 56% of the ball in the opening spell. Italy have looked the stronger in the lineout and at the scrum, but in open play, Wales have just had too much.
3.24pmItaly's only points so far have come from fly-half Tommaso Allan, who is making his Six Nations debut.
3.25pmThe players are heading back out ready for the second half.
41 minPriestland gets the game back underway.
42 minWales quickly get the lineout, and North almost manages to slip through the Italians' fingers, but Campagnaro just manages to hold him back. Alun Wyn Jones keeps the move alive for the hosts, but Parisse manages to steal it away for the visitors.
43 minCampagnaro makes a brilliant run and appears to have scored Italy's opening try of the match, but the TV referee is going to review the play.
43 minTRY! Wales 17-8 Italy (Campagnaro)
43 minMISSED CONVERSION! Wales 17-8 Italy (Allan)
43 minAfter winning the ball back from the Welsh side, Campagnaro initially throws it out wide for Sarto, who kicks it forward for his teammates to take it over. There was a hint of forward to Campagnaro's pass, but as his hands didn't move forward the officials let it stand. Italy are right back in the match.
45 minMISSED PENALTY! Leigh Halfpenny is quickly called into action at the other end following an obstruction by the visitors, but it's a very tight angle, and he can't quite slice it inside the posts.
48 minItaly will have a chance to reduce Wales's lead further after Paul James gives away a penalty for coming in from the side in the lineout. Allan will get a chance to make amends for the conversion miss.
49 minMISSED PENALTY! Given that the roof is closed, the kicking has not been good since the restart! It's not the trickiest of attempts for the young Italian fly-half but it drifted wide at the last moment to leave Italy nine points down.
52 minItaly have made a superb start to the second half, camping out in Wales territory since the game resumed, while Wales have looked somewhat flat. However, while trying to force their way over for a second, Italy give Wales some breathing space when Bergamasco concedes a penalty.
54 minPriestland intercepts a pass intended for Parisse near the half-way line to give Wales their best attacking opportunity of the second half.
56 minWales have a lineout, which Tipuric collects and passes it to Priestland. The fly-half is tackled just short, and tries to offload it before he's knocked into touch, but he doesn't have time to look for a teammate, giving the ball to Parisse instead, before Allan kicks it into touch.
58 minWales are looking a lot more lively now. Cuthbert is almost in for his second of the afternoon, but a desperate tackle from Gori does just enough to stop him crossing the line, and allows Sgarbi to try a counter-attack for Italy.
60 minPaul James gives away a penalty for the second time this half for taking out Bergamasco. The decision seems a little harsh to be honest, and he shakes his head as the referee announces his decision. The penalty allows McLean to give Italy a line out just a couple of metres from the Wales try line.
62 minHibbard manages to get Wales out of trouble, snatching the ball away from Allan as the Azzuri try to slip through the Wales defences. Wales win a lineout of their own, from which Phillips manages to kick it deep, but Italy are swiftly back on the offensive.
64 minIt might be time for Warren Gatland, who is celebrating his sixth anniversary in charge of the side this weekend, to consider bringing on some of his replacements, as the home side are starting to look a little weary. Campagnaro tries to smash his way through again, but a superb tackle from Faletau prevents the try.
65 minWales are indeed making changes, and it's a popular one with the crowd as Sam Warburton comes on for Dan Lydiate. Rhodri Jones is on as well, taking over from Adam Jones.
67 minItaly have a scrum, but the ball isn't put in straight, giving Wales another penalty, and they're going to go for goal. This could be enough to put the game beyond Italy.
67 minPENALTY! Wales 20-8 Italy (Halfpenny)
68 minIt's an easy shot for Halfpenny from directly in front of the posts, and he drives it low to leave Wales 12 points clear with a little over 10 minutes left to play.
70 minTRY! Wales 20-13 Italy (Campagnaro)
70 minItaly have given themselves a chance in the final 10 minutes as Campagnaro scores his second try of the game. It was a mistake from the usually reliable Halfpenny, who was looking to find Roberts with a pass, but he wasn't looking properly, and Campagnaro intercepted the pass before darting back to keep Italy in contention.
71 minCONVERSION! Wales 20-15 Italy (Allan)
73 minWales had started to look like they were shutting down with a decent lead and the clock running down, but there's a lot more urgency about their play now, and they've forced another penalty when Zanni was offside.
74 minPENALTY! Wales 23-15 Italy (Halfpenny)
74 minOnce again Halfpenny makes it look easy, but Wales will still have to be careful in the final five minutes, as Italy have proved in this second half that they're not giving up on this game.
76 minItaly have a lineout but Wales manage to steal it. This could give the home side the opportunity to put the result beyond doubt if they can find a way to add their third try.
78 minItaly are doing just enough to stop Wales scoring again, holding Priestland up at the half-way line. The visitors briefly regain possession, but Alun Wyn Jones gets it back for Wales.
79 minCampagnaro, who has been just superb for Italy this afternoon, makes yet another crucial play, tackling Jones short of the try line.
80+1 minItaly win a late scrum at the half-way line, but the clock ticks over into the 81st minute as it's taken, so this will be the last action of the game.
80+2 minItaly do well to keep the ball alive but Wales manage to steal it back, and it looks like they're going to push for a late try of their own.
80+2 minFULL TIME: Wales 23-15 Italy
4.17pmDespite a bit of a second-half scare, Wales have started the defence of their Six Nations title with a win over Italy.
4.19pmThe visitors put up a good fight, defending well in the first half before Michele Campagnaro led the Italy comeback. If the Azzuri can recreate today's performance throughout this tournament, they could certainly cause a couple of upsets.
4.20pmNext up for Wales is a trip to Ireland next Saturday. They'll need a lot of work before then, as they won't get away with as many mistakes in Dublin. Meanwhile, it's another away fixture for Italy as they face France.
4.22pmThat's all from the Millennium Stadium this afternoon, but stick around for build-up and live commentary from England's opening game of the tournament against France, and join us again tomorrow when Ireland face Scotland. Until then, thanks for joining me this afternoon, goodbye!