Hello and welcome to live coverage of the second women's US Open semi-final, between world number one and defending champion Serena Williams and fifth seed Li Na.

So it will be a repeat of last year's final between world number one, and defending champion, Serena Williams and world number two Victoria Azarenka.

WILLIAMS 6-0 6-3 - GAME, SET & MATCH! And this time Williams finally does book her place in the final, a big serve down the centre of the court finally securing the match as Li puts her return into the net.

WILLIAMS 6-0 5-3 - Heavyweight hitting onto the baseline from Williams followed by heavywight screaming of "come on" not once but twice as she moves to within two points of the final again. Li gets one point back after a netcord from Serena sees the ball sit up enough for Li to hit down at her opponent's feet. Williams is furious with herself when another forehand goes long to allow Li to level at 30-all but she earns a seventh match point when Li hits long, this time on her own serve ...

WILLIAMS 6-0 5-3 - And eventually Li goes on to hold when Williams goes long with a forehand down the centre of the court. The world number one and defending champion will have to serve for a place in the final.

WILLIAMS 6-0 5-2 - Li finally gets the backhand down the line right so safe this one as Williams nets her forehand reply. A double fault, Li's fourth, wastes a game point before a forehand long hands Williams a fourth match point. This time the world number one nets a forehand return and a fifth goes begging on a cross court forehand wide from mid-court. Williams is also unable to take advantage of a sixth after a series of huge forehands from Li combined with a smash winner across court...

WILLIAMS 6-0 5-2 - Another backhand ends in the net from Li and it hands Williams a first match point. A clever serve down the centre of the court saves it for the fifth seed as Williams is only able to net her forehand return but Williams fashions another chance with a brilliant forehand passing shot winner across court. It goes begging on a backhand pulled wide across court but another cross court forehand return winner brings up a third match point...

WILLIAMS 6-0 5-2 - Williams finds her fifth ace of the match to seal a service hold to 15 and consolidate the break. That hold from the defending champion leaves fifth seed Li Na serving to keep the match alive after the change of ends.

WILLIAMS 6-0 4-2 - BREAK! Another stunning rally from Williams as she pushes Li wider and wider across court before eventually getting the down the line backhand and hitting back behind the scampering Li to get off the mark in the game. The world number one goes back to the same spot on the next point to level at 30-all before a netted backhand from Li hands Williams another break point. Williams gets a little lucky with a net-cord as it prompts Li to loop her forehand long and concede the break

WILLIAMS 6-0 3-2 - Williams wrestles the advantage back again in this match as she comes through another fairly tough hold, to 30, with a kicking serve out wide that Li cannot return in play. The American leads again on serve and the momentum definitely feels like it has shifted back to the defending champion.

WILLIAMS 6-0 2-2 - BREAK! Li races out to 40-0 lead before Williams pegs her back with a series of big shots from the baseline, the last of the game points going astray with a netted backhand down the line from Li. From there Serena goes on to break back with an inside-out cross court forehand sent back into the net again by Li. Back on serve in this second set.

WILLIAMS 6-0 1-2 - BREAK! Williams throws in a double fault and a forehand error to hand Li two break points. The first goes begging on a huge serve from the American and Serena saves the second with a blistering backhand winner across court. A forehand drive volley winner and a yell of "come on" brings up a game point but she is unable to take advantage and Li fashions a third break point. This time she does make her presence felt, driving through a cross court forehand that Serena can only net

WILLIAMS 6-0 1-1 - The crowd errupts as Li picks up a first game of the match, a hold to love, secured with a trip into the net and a forehand winner. Li plays up to the crowd but there's no smile to speak of.

WILLIAMS 6-0 1-0 - A slightly tougher game for Williams on serve as Li pushes her to 30-all before netting a forehand to allow the American a game point. It's a game point that Williams takes full advantage of with another big first serve that Li cannot return in play. That's seven straight games from the world number one now.

The one scrap of comfort for Li is that on the one occasion she has beaten Williams in the past, she did so after coming back from losing the first set 6-0. That was in Stuttgart way back in 2008.

WILLIAMS 6-0 - SET! Ouch! Another forehand gets away from Li as Williams sets a bagel first set in just 29 minutes. That's three straight bagel set from Williams now.

WILLIAMS 5-0 - Williams leaps around the net - a backhand drive volley here, a forehand volley there - to bring up a game point when Li pulls a cross court forehand wide. Game point Williams. And the American secures it at the first attempt with another trip up the court and a forehand drive volley that a luging Li can only return wide down the line off the forehand wing. The fifth seed will have to serve to stay in the opening set after the change of ends.

WILLIAMS 4-0 - BREAK! Li mis-times a forehand to gift Williams another break point. Li does well to pepper the baseline with forehand after forehand but the ball is getting increasingly lower and eventually, when Li goes for the change-of-direction forehand across court, she catches the top of the tape and bounces wide.

WILIAMS 3-0 - Williams produces the first ace of the match to earn herself a couple of game points. She's unable to take advantage of either and very nearly hands Li a break back point when a smash winner leaves her perilously close to touching the net before the double bounce. She just manages it but puts a forehand wide down the line to concede the break point. But a sliced backhand return from Li drops short into the net and Williams goes on to hold at the next attempt.

WILLIAMS 2-0 - BREAK! A superb angle on the cross court forehand from Williams draws the forehand well long down the line from Li and the American goes on to earn herself an early break point. Li does fantastically well on defence with a backhand lob right on to the baseline getting her back in the game. But she can't hold on long enough, eventually netting a forehand to gift Williams an early break.

WILLIAMS 1-0 - Three huge serves and three return errors from Williams and she has three early game points. The first rally of the match comes on the last point of the game, Williams picking up that point with a backhand winner to secure the love hold to open with.