Please note that play is scheduled to start after 6.45pm.
11.59pmThat was one of the most one-sided Grand Slam semi-finals I can remember.
Williams will definitely not have it as easy in tomorrow night's final, when she faces world number one Victoria Azarenka. Sports Mole will be here for that, however our live coverage on Saturday will begin just before 4pm (UK time) in anticipation of Andy Murray's semi-final clash with Tomas Berdych. Join us then. Good night.
11.58pmWilliams converted 4/10 break points. Errani did not create a single break point.
11.57pmIt took Williams 64 minutes to win that match. The American made nine aces, while Errani made none.
Williams 6-1 6-2 ErraniGame set and match! Williams converts her second match point with a superb second-serve ace.
11.35pmA number of bookmakers are currently offering odds of 100-1 on Errani winning this match. For those of you that don't understand betting, let me explain. If you place �1 on Errani... you will lose �1.
Williams 6-1 2-0* ErraniWilliams holds to 15. A ripple of subdued, polite applause is heard from the crowd, who are clearly disappointed with the non-contest that they are observing.
Williams 6-1 *1-0 ErraniWilliams breaks! She treats the Italian's second serve with complete and utter contempt, as she swats it back onto the baseline with plenty of interest.
10.48pmThe players have finished their warm up and the match is just minutes away...
10.46amThat statistic should perhaps be taken with a pinch of salt, as their last meeting was in 2009 and since then the Italian has made great strides. Nevertheless, anything other than a Serena win in straight sets would be a big shock.
10.45pmSerena, who is undoubtably the best player in the women's game right now, has a 3-0 winning record against Errani.
10.44pmThat last semi-final lasted 162 minutes, but I would be very surprised if this one even reached the two-hour mark.
10.36pmAnyway, that's all from me tonight. I'll now hand you over to the ever-insightful Robert Summerscales who will guide you through the second semi-final between Serena Williams and Sara Errani. Enjoy!
10.32pmVictoria Azarenka: "Maria is such a great player and she came out firing and didn't give me an opportunity.
"I didn't try to focus on the score and give whatever it takes.
"It's my first final but I want to play it already!"
10.31pmMeanwhile, Sharapova's game was ridden with 42 unforced errors and 10 double faults as she is beaten for the second time this year by Azarenka at a Grand Slam.
10.29pmThe Belarusian looked like she hadn't quite got out of bed in that first set as she was wiped off the court 6-2. However, she fought back and played some quite devastating tennis in the next two sets to seal her place in tomorrow's final.
10.28pmSharapova hits long which means that Victoria Azarenka is through to her first US Open final!
10.27pmGAME, SET AND MATCH! Azarenka 3-6 6-2 6-4 Sharapova
10.25pmAzarenka has match point but then hits a forehand wide. Tension here! Deuce.
10.23But Sharapova hits a mighty ace to claw a point back.
10.19pmOne of the clowns from LMFAO is in the crowd on Ashe supporting Azarenka.
Azarenka 3-6 6-2 4-4* SharapovaIt's the third time Sharapova has closed out a game with an ace and it's now 4-4. Azarenka asked plenty of questions in that one but the 2006 champion answered them firmly.
10.14pmThe Russian definitely hits long this time and it's 30-30.
10.13pmSharapova hits a forehand that looks out but Azarenka doesn't challenge, 15-15. Replays show that it looked past the baseline though.
10.01pmA couple of errors not doing Sharapova any favours. She was 40-0 but now it's deuce.
Azarenka 3-6 6-2 3-2* SharapovaFantastic from Azarenka. She gets the advantage before scuttling around the court keeping the next point alive. The Belarusian then hits a backhand down the line to hold. Neither of these two are giving this one up easily.
9.53pmSharapova digging her heels in her. She brings it to deuce from 40-0 on the Azarenka serve.
Azarenka 3-6 6-2 *2-2 SharapovaShe does it the hard way but Sharapova holds after saving three break points. That was an important game and the Russian has come out the other side intact.
9.48pmThis time it's Azarenka who can't convert her break point as Sharapova hammers a backhand winner home.
9.47pmBoom! Another game point goes begging for Sharapova as Azarenka unleashes a savage forehand winner into the corner.
9.45pmSharapova has game point but is struggling to close this out. Back to deuce.
9.42pmAzarenka has two break points but squanders them both. Deuce.
9.40pmHere's a ridiculous stat: the last time that Sharapova lost after winning the first set was TWO YEARS AGO.
9.31pmOh my word. Azarenka moves to the net to hit a simple volley, but somehow she puts it into the net.
9.30pmAzarenka makes life difficult to go 0-30 ahead on the Sharapova serve but the Russian whacks a forehand winner into the corner before taking the next point, 30-30.
Azarenka 3-6 6-2 1-0* SharapovaThe two keep at it with the heavy hitting before Azarenka eventually holds. All eyes on Sharapova now as she steps up to serve.
9.26pmSharapova hits her 24th winner to make it 15-15.
9.25pmOkay then, it'll be Azarenka to open the serving in this third and final set. Here we go. Something's gotta give.
9.24pmAnd here she is, right on cue, with the 10 minutes all but up.
9.23pmAzarenka's out first and is hitting a few balls out on court. We're still waiting for Sharapova...
9.22pmIt's only ever gone to three sets in two of the nine meetings between these two. Azarenka won both of them, back in 2009, in Beijing and Los Angeles.
9.19pmAs mentioned, neither of these ladies have lost a three-set match this year. Azarenka has won all 11 of hers while Sharapova has been victorious in the 12 that she has competed in.
9.16pmThe two players have left the court temporarily to change outfits and grab a quick breather. They certainly deserve it, it's been relentless out on court.
9.13pmAzarenka breaks Sharapova's serve again and takes the second set 6-2. The world number one controlled that pretty much from start to finish while the Russian looked very shakey indeed. This one's going to a third set!
8.53pmBoth women wailing like banshees there as they battle it out in another rally. Azarenka eventually gets the point after Sharapova hits wide.
Azarenka 3-6 4-1* SharapovaAzarenka holds to win her fourth game in a rwo. It's looking good for the world number one at the moment. Are we going into a third set? Remember, neither has lost a three-set match this year.
8.47pmIs there a Grand Slam champion playing at the moment with as unreliable a serve as Sharapova? It's costing her dearly here.
Azarenka 3-6 *3-1 SharapovaBREAK! It's another double fault from Sharapova and it's another break for Azarenka. The momentum has shifted dramatically in this one.
8.45pmAnother thrilling rally brings up a break point for Azarenka.
8.38pmSharapova really lambasting herself when she's making errors. Very unlike her.
Azarenka 3-6 *1-1 SharapovaBREAK BACK! A weak forehand from Sharapova brings up a break point before the Russian hits the net again. The Belarusian breaks back and we're all square at 1-1.
8.36pmSharapova has the chance to hold following another ace but it's back to deuce after the world number three hits wide.
8.35pmThe Russian brings up game point with an ace but Azarenka makes it deuce with a very purposeful backhand winner.
8.33pmSharapova hits long with a backhand and it's 30-30.
Azarenka 3-6 0-1* SharapovaBREAK! The Russian brings up the break point with a sizzling backhand before Azarenka hits wide. The world number one is on real trouble now. Staggering to think that's she hit only the one winner so far.
8.30pmIt was 40-15 but Sharapova brings it to deuce.
8.27pmIt'll be Azarenka to open the serving in this second set, a set that the world number one has to win to keep her US Open dreams alive.
8.26pmAfter serving five double faults, Sharapova seals the openning set 6-3 with an ace. The Russian started in unstoppable form but suffered a few blips as she tried to close out the set. However, she eventually did and has now one foot in tomorrow's final. Azarenka got better as it went on but will need to improve quickly if she is to get herself back in this one.
8.23pmSharapova has a set point but whacks the ball into the net and we're back to deuce. Tense stuff out there right about now.
8.22pmThe Russian was facing two break points, but now we're at deuce.
8.20pmIt's a fifth double fault for Sharapova, 15-30.
Azarenka 3-5* SharapovaIt's Sharapova's turn to hit the net and Azarenka holds again. The Russian will get a second chance to serve out this first set.
8.16pmThese two really slog through a rally before Azarenka hits the net with a forehand on the move, 30-15.
Azarenka *2-5 SharapovaBREAK BACK! The double faults come back to haunt Sharapova as a first brings up a break point for Azarenka before a second hands the world number one the break. A route back into this one for the Belarusian?
Azarenka 1-5* SharapovaBREAK! Oh yes. A thunderous forehand volley makes it 0-40 before Azarenka double faults to give the Russian another break. This is very one sided right now. Sharapova serving for the set.
8.08pmAzarenka hits the net with a forehand and it's 0-30. Chance for Sharapova?
8.01pmIt's relentless from Sharapova as another powerful backhand forces Azarenka into the error and it's deuce.
7.58pmSharapova won't be taking this lead for granted, however. She was 2-0 up in the final of the Aussie Open but only won one more game as she was beaten 6-3 6-0 by Azarenka.
Azarenka *0-3 SharapovaThe Russian's groundstrokes look fantastic so far as she holds for a second time. She's very much up for this one. Meanwhile, Azarenka has it all to do in this first set.
7.53pmSharapova hits her first double fault of the match, 15-15.
Azarenka 0-2* SharapovaBREAK! It's a great start for Sharapova as Azarenka double faults to hand the Russian the break.
7.50pmWhoosh. Sharapova unleashes a powerful forehand winner, 30-30.
Azarenka *0-1 SharapovaSome great hitting already from these two but Sharapova comes through to hold. This has the makings of a cracker.
7.44pmSharapova gets the ball rolling with a sweet forehand winner.
7.43pmHere we go then in the first of the women's semi-finals here at the US Open. It's Victoria Azarenaka versus Maria Sharapova and the Russian will serve first.
7.38pmIt's looking like a very hot day indeed in the Big Apple. I wonder which player that will affect the most?
7.35pmThe players emerge from the locker room to the throbbing soundtrack of Fatboy Slim's 'Right Here, Right Now'. Not that Azarenka can here, she's got her headphones on.
7.34pmAzarenka: "You have to play every ball and fight as hard as you can because Maria is a great champion."
7.33pmSharapova: "I've been playing well these last two weeks and am very excited about today."
7.31pmThis is Azarenka's first semi-final here at the US Open, while is is the third time that Sharapova has been at this stage of the competition.
7.25pmVictoria Azarenka failed to drop a set until she got to the quarter-finals where she met defending champion Sam Stosur. The two engaged in one of the most thrilling matches of the tournament before the Belarusian extended her three-set record for this year to 11-0 with a 7-5 triumph in a deciding tie-break.
7.23pmMaria Sharapova progressed through to the fourth round with relative ease before she had to see off Nadia Petrova 6-1 4-6 6-4. Then came her ill-tempered quarter-final against Marion Bartoli which she came through 3-6 6-3 6-4.
7.21pmBefore the players enter the Arthur Ashe Stadium, let's remind ourselves how they got to the semi-finals...
7.18pmThe Bryans are currently lifting the double trophy and lapping up the cheers of their home crowd. And why not?
7.12pmWhat is also means is that we're edging closer to out first women's semi-final here in New York.
7.11pmWhat that doubles result means is that the Bryans are now just one Grand Slam doubles title behind the record-holding Williams sisters in the all-time rankings.
7.08pmSo, the Bryan brothers are crowned doubles champions with a straight-sets victory over Leander Paes and Radek Stepanke to win their 12th Grand Slam doubles title. What a team.
7.06pmGAME, SET AND MATCH! Bryan/Bryan 6-3 6-4 Paes/Stepankek
7.01pmUPDATE: The Bryan brothers are 5-4 up in the second set against Paes/Stepanek and will now serve for the men's doubles title that they last won in 2010.
6.58pmAs for the second, it's extremely hard to look past Serena Williams. Errani is a tidy, tireless player but she's coming up against a force of nature later this evening in the American. Furthermore, I think that Williams will go on to clinch her fourth title at Flushing Meadows. She's been phenomenal these past few months.
6.55pmI'm thinking that Victoria Azarenka will win this first one against Maria Sharapova. I reckon that it'll go to three sets but the Belarusian has been the more consistent player of the two during this tournament and that will get her over the line.
6.53pmRight, time to stick my neck on the line and make some predictions...
6.49pmUPDATE: It's still close in the second set of the men's doubles final as the Bryans lead 3-2 and are on serve.
6.44pmHowever, it'll be interesting if this match goes to three sets because both women have excellent records when it comes to those sort of contests this season. Azarenka is 11-0, while Sharapova is 12-0.
6.39pmThey've met twice this year, with the world number one dishing out a fairly sound beating to the Russian each time. The first was in the final of the Australian Open back in January which Azarenka won 6-3 6-0. The next was in the final at Indian Wells two months later with the Belarusian winning that one 6-2 6-3.
6.37pmTurning our attention back to the Azarenka/Sharapova battle and there is very little to seperate these two. They've met nine times in total, but Azarenka edges it 5-4 on the head to head.
6.34pmThe Bryans took the opening set 6-3 and are 2-0 up in the second following an early break, so it looks like that one could be over sooner rather than later.
6.30pmIt's worth pointing out that before Azarenka and Sharapova can take to the court for tis evening's first semi-final, they'll have to wait for the conclusion of the men's doubles final which features the Bryan brothers taking on the team of Radek Stepanke and Leander Paes.
6.28pmYou can view the order of play for tomorrow here.
6.26pmThe winners of those two matches will then meet in tomorrow's final following the conclusion of the two men's semi-finals.
6.24pmUp first is world number one Victoria Azarenka taking on world number three Maria Sharapova (earplugs at the ready), while three-time champion Serena Williams meets 10th seed Sara Errani after that one.
6.21pmWe've got a couple of cracking matches in store today as the women play out their two semi-finals inside the famous Arthur Ashe Stadium.
6.18pmHello there and a big Sports Mole welcome to you all on this, day 12, of the US Open in Flushing Meadows, New York.