Live Commentary: Madison Keys vs. Venus Williams - as it happened

Hello, and welcome to Sports Mole's live coverage of the Australian Open quarter-final between Madison Keys and Venus Williams.

Today's schedule on Rod Laver Arena includes a Grand Slam champion in every match, but we kick off with arguably the most intriguing of the lot. Madison Keys - the great American hope who has powered her way into her first Grand Slam quarter-final - against a player in Venus Williams who she probably grew up wanting to emulate.

We are only a few minutes away from that encounter getting underway, but before we get started, let me tell you what we have coming up after this contest. Venus's sister Serena, a multiple-time winner in Melbourne, will go toe-to-toe with last year's runner-up Dominika Cibulkova, while the day session concludes with a real humdinger of a men's game between defending champion Stanislas Wawrinka and Kei Nishikori.

The night session is headlined by Novak Djokovic's match with the big-serving Milos Raonic. The world number one will probably be hoping that the temperature drops in time to go some way to neutralising the Canadian's huge serve.

The one and only meeting between these two players came on the clay in Charleston in 2013. Venus ran out a convincing 6-4 6-4 winner on that occasion, but since that match, Keys has really started to fulfil her undoubted potential. Both possess huge weapons off the ground but with the 19-year-old growing in stature with every match, she is arguably the favourite to prevail against a player 15 years her senior.

Anyway, the two players are ready to get started. It will be Venus to serve first. Game on!

Venus opens with a hooked backhand that goes wide before Keys gets fortunate with a net cord to advance to 0-30. The danger signs are there already but the 34-year-old records four successive points - two which were gifted to her by Keys - to secure a hold in the opening game.

There are a few nerves in the arms of Keys and two errors allow Venus to build a 30-0 lead but on the next point, Keys steps in to put away a forehand to reduce the deficit. The youngster gets to game point but Venus forces her onto the defensive with a return and we get to deuce. Venus hangs around but an ace and a stunning backhand winner ensures that Keys gets on the scoreboard.

A lucky net cord gets Venus off to the perfect start before two big serves are struck out by Keys. However, the seven-time major winner makes two mistakes to allow Keys a way back into the game before the younger of the two American hitters hooks a return wide.

After the first two points are shared, Keys swings an ace out wide before Venus drives the following return long of the baseline. A second ace in the game wraps it up for Keys, who is looking increasingly composed on the Rod Laver Arena.

Venus is mixing up her serves to good effect and after two are returned off target by Keys, the 18th seed drives down an ace. A love hold is converted when Keys is unable to handle a serve to her backhand side.

A weak second serve from Keys gives Venus the chance of 0-30 but she puts too much on her return. Keys's serve has dropped off in this game and Venus knows it but despite getting to deuce, the youngster comes through with a fine hold to stay on level terms.

BREAK! Keys displays her power to generate a 0-30 advantage but Venus really comes out swinging on the next to overpower her opponent. However, Keys isn't discouraged, and the 19-year-old hammers a return into the corner for two break points. Venus looks in control of the next rally but Keys steps in to put away a smash to break through.

This is turning into a really assured performance from Keys. When she takes the initiative, she is generally coming out on top. Venus is doing a lot of running and stretching but so far, her efforts aren't getting the reward. An inside-out forehand earns Keys two game points before Venus hits a second-serve return long.

SET! Under the impression that Keys is all about power? Think again. She glides into the net to put away the deftest of volleys before Venus throws in a double fault to give her opponent 0-30. It's all Keys now and she brings up three set points when Venus sends a backhand into the net. She wastes no time in moving into a one-set lead with a bludgeoning forehand return and Venus has it all to do here.

She appeared nervous during the early stages but it's Madison Keys who is looking like the player with mountains of experience here. She is bulldozing her way past Venus right now and unless her level drops, she should win this match.

It's more of the same from Keys, who eases into a 40-0 lead with more venomous hitting. A forehand winner and huge first serve seals a love hold. You feel as though Venus needs to hold in the next game or this match could run away from her.

That's better from the 2003 champion, who responds with three straight points to move to the brink of the game. Keys stays active with a forehand winner that wrong-foots her opponent but a fine serve down the middle helps Venus to the game.

BREAK! Hmmm, maybe everyone - myself included - were getting ahead of themselves. Keys opens with a double fault, and she's visibly nervous. She takes the next point but her game unravels over the next three points to allow Venus to edge a break in front in this second set.

After the opening two points are shared, the court opens up for Keys to make what should be a relatively routine passing shot but she over-hits it by several yards. The 19-year-old hangs around until 40-30 but she can't return Venus's next serve and she consolidates the break.

BREAK! Keys has had a quick word with the umpire - maybe she needs the trainer? She shows no weakness in advancing into a 30-0 lead but after netting for 30-30, she grimaces and clutches her left thigh. She's really struggling and Venus seals the double break. This isn't looking good...

After an assessment from the trainer and doctor, Keys has left the court to take some painkillers, but regardless of whether they help or not, this contest has turned around completely.

Keys has returned with huge strapping to the left thigh but she is going to continue. This next game should be interesting.

BREAK! To some extent, Keys has nothing to lose now and she comes out with that mentality and breaks to love! Understandably, she's going for everything, and on that occasion, it paid off.

Keys takes the first two points on her serve, but Venus stops a rot of losing six points in a row after moving her opponent around the court. Keys won't want too many points like that. She's in a lot of discomfort but she finds some magic at the net to reduce the deficit to one. Keys needs to be careful here, though. She doesn't want to aggravate an injury that might keep her out of a semi-final anyway.

BREAK! Keys is absolutely leathering the ball now and Venus is having to work hard to stay in each point. At 15-15, Keys is all over a Venus second serve and she repeats the feat on the next point. She has two break points for a level game, and for a third point in succession, the return gets the job done. Remarkable stuff. She has won 12 of the last 15 points.

BREAK! Venus finally has some success against the injured Keys to open up a 0-30 lead. The 19-year-old replies with an ace but on the next point, the 18th seed works Keys around the court before the error comes. Keys shows tremendous guts to get back to deuce but Venus has worked out that she is struggling on the backhand side and that's enough to get back in front. The trainer is back out, and if Keys loses this set, I'd say there is a chance she may pull out, but we will see.

SET! Two returns from Keys fail to hit their intended target to see Venus move two points from the set but she remains active when Venus goes long. However, two set points are created when Keys hits a wayward forehand, and it's sealed on the first with an ace down the middle.

Keys is continuing but she winces when netting a backhand on the opening point. Venus senses her moment but despite creating two break points, Keys mixes her trademark power with a soft touch at the net to seal an impressive hold. She needed that, and I think it's safe to say she won't be retiring from this match.

It's important here for Venus to not offer any more encouragement to her opponent but when an unforced error hands Keys 0-30, the danger signs are there for the 18th seed. She finds a way to fight back, though, through a mixture of solid first serves and Keys only finding the net.

BREAK! Venus seems undecided whether to attack Keys or make her work for every point and it's not helping her cause. However, despite falling 40-15 behind, she hangs tough with her opponent to get to deuce, and that's enough to heap enough pressure on Keys to secure the break of serve when the 19-year-old blazes long.

Venus quickly records four points in a row and the match is starting to slip away from Keys. She is fighting on valiantly but Williams looks in control of her game.

Keys hits two shots into the net to give Venus the lead but it's the points either side of 15-30 that suggest that Keys isn't ready to give up on this. She's continuing to go for broke with her forehand and it gets her an imperative hold.

BREAK! Keys launches into a forehand from the baseline and it drops inside the court to get her to 15-15. Venus regains a slender lead but back comes Keys who blasts a cross-court backhand to bring up break point. It's saved by the 18th seed, who saves a second soon afterwards, but on the third occasion, the 19-year-old levels after Williams goes wide from inside the court. Drama!

BREAK! Keys takes the opening point but two unforced errors soon gift Venus the advantage. A third baseline mistake gives further encouragement to the 34-year-old, who has two break points, and although the first goes begging, Venus produces a big play during the next rally, pounding the Keys backhand before driving a winner down the line.

BREAK! We've had 10 breaks of serve in this match so far and we are soon on our way to an 11th when Keys lashes the ball around the court before sealing two points with winners. Venus finds a way back to 30-30 but another dominant point creates the break point. Venus throws down a second serve and it's enough to give the advantage to Keys, who thunders down a forehand winner. It's getting to a tense time now!

We've seen the tide change numerous times in this match but is this the moment that Keys makes her move? More unbelievably strong hitting, given the condition of her thigh, from the younger of the two Americans sees her hold to 15 and when we return, Venus will be serving to remain in the tournament.

MATCH! Two shots into the net have Venus in huge trouble at 0-30. Keys is two points away from a remarkable triumph! Make that one. Unbelievable stuff! Venus hammers a forehand at the net but Keys latches onto it to divert it into the open court. Three match points, but she only needs one! Keys powers another ridiculous forehand into the corner to complete the win. Rod Laver Arena is on its feet.

How on earth has Madison Keys managed that? Only she will know. That was a stunning recovery. On more than one occasion, she looked down and out with a thigh problem hampering her backhand and general movement, but somehow, she has made it into her first Grand Slam semi-final. She will play the winner of the next match between Serena Williams and Dominika Cibulkova.

That will be all from this quarter-final, but we hope that you stick around for our second helping in a few minutes times. See you then!