LIVE: Coco Gauff 6-34-6 Elena Rybakina in US Open semi-final - winner of deciding set will play Aryna Sabalenka in Saturday's final
Rybakina will become world number one for first time on Monday
Fourth seed Gauff bidding for second New York title
Earlier, two-time defending champion Sabalenka beat Jessica Pegula 7-5 6-2 to reach fourth successive New York final
American third seed Pegula beaten by Belarusian for third year in a row at Flushing Meadows
*Gauff 6-3 4-6 2-3 Rybakina
Eight first serves in so far in this third set and eight points won for Elena Rybakina.
It's pretty clear what her way home is from here. But, of course, it's a whole lot easier said than done.
Still on serve in the decider.
Gauff 6-3 4-6 2-2 Rybakina*
It's Coco Gauff's turn for a straightforward hold.
An ace helps the American fourth seed on her way. Getting your first serve in really will do wonders.
*Gauff 6-3 4-6 1-2 Rybakina
It's not happened too often tonight but Elena Rybakina finds her first serve in this game.
Back-to-back aces - one out wide, the next down the T - secure a comfortable hold. A precious thing at this stage of a Grand Slam semi-final.
Gauff 6-3 4-6 1-1 Rybakina*
Coco Gauff is on the board in this deciding set.
The former champion was really made to work for it, though.
At 40-15, that didn't seem likely but Elena Rybakina's blistering return makes it 40-30 and she quickly gets to deuce.
Advantage comes and goes for the American but she earns it again, and this time converts. A big hold for the fourth seed.
*Gauff 6-3 4-6 0-1 Rybakina
Image source, Getty ImagesAfter failing to get a first serve in four points in a row, Elena Rybakina finds it at the crucial moment at 30-30.
Great power and direction out wide make it 40-30 and when Coco Gauff pulls a backhand wide, a tricky service game has been negotiated by the second seed.
Gauff 6-3 4-6 0-0 Rybakina*
We're going the distance!
Elena Rybakina strikes at the crucial moment but that was as much about an untimely off game for Coco Gauff.
The American wavered for the first time in the match, really, and the soon-to-be world number one was there to capitalise.
Gauff 6-3 4-5 Rybakina*
Good, deep return from Elena Rybakina and Coco Gauff goes long.
It's 15-30. Is this the chance for Rybakina?
It certainly is now - a double fault and the Kazakh has two set points.
*Gauff 6-3 4-5 Rybakina
Image source, Getty ImagesThat's the settler Elena Rybakina needed.
She holds comfortably and it'll be over to Coco Gauff to serve to stay in the second set.
Gauff 6-3 4-4 Rybakina*
Coco Gauff finds her first serve this time and we're level again in the second set.
The American has been on it tonight. Even after going a break down, her head didn't drop and now she'll be looking to get this match done in two.
*Gauff 6-3 3-4 Rybakina
Elena Rybakina has been dominant on serve all championship but not so tonight.
It's just not clicking for the second seed and Coco Gauff is taking full advantage.
The American earns two break points when Rybakina finds the net but the first goes begging as she puts her drop shot wide.
No bother, Gauff converts the second with a solid return followed by a powerful backhand that Rybakina can only put into the net.
Back on serve in the second.
Gauff 6-3 2-4 Rybakina*
Coco Gauff shrugs off another double fault, her second is as many service games, to hold to 15.
She won't want to make a habit of those as this match goes on but it doesn't cost her this time.
Still just a break in it in this second set.
*Gauff 6-3 1-4 Rybakina
Yep, here comes Elena Rybakina.
Much more like it from the Australian Open champion as she holds to love.
A dominant service game.
Gauff 6-3 1-3 Rybakina*
After a double fault to start the game, there are the first signs of nerves from the American crowd as Coco Gauff puts another first serve into the net at 15-15.
It turns out they were right to be a little nervous because Elena Rybakina is starting to step things up.
The second seed brings up break point by ripping a powerful backhand cross-court, too strong for Gauff this time, and earns her first break of the match.
*denotes next to serve
*Gauff 6-3 1-2 Rybakina
A double fault gives Coco Gauff a chance at 30-30 but Elena Rybakina comes through unscathed.
There are signs of her power coming to the fore in the last rally of the game with Gauff pushed back and only able to plink a tame forehand into the net.
Gauff 6-3 1-1 Rybakina*
Image source, Getty ImagesSuperb from Coco Gauff but that's a missed opportunity for Elena Rybakina.
Rybakina had a clear opening at 0-30 and was in control of the rally with the chance to bring up three break points, only to put a backhand slice into the net.
From there, Gauff - roared on by the crowd - is not going to be stopped with an overhead smash making it 40-30 before Rybakina goes long.
*Gauff 6-3 0-1 Rybakina
Just what Elena Rybakina needed to start the second set, a relatively comfortable hold to 15.
Coco Gauff gets it to 15-15 but Rybakina soon shuts down any thoughts the American might break with a dismissive forehand, smoked into the corner.
Gauff 6-3 0-0 Rybakina*
Thanks, Emma.
How impressive was Coco Gauff in that first set?
Elena Rybakina will be world number one come Monday but she's got it all to do if she's to have a nice, shiny US Open trophy as well.
Can Coco Gauff see this out, or will Elena Rybakina find an answer?
To take you through the rest of this match, here's Sam Drury.
Gauff 6-3 Rybakina
Image source, Getty ImagesCoco Gauff is moving with such freedom, none of the nerves we saw yesterday against Mirra Andreeva are on show.
A smash winner puts her 30-0 ahead, then she picks up what seemed a definite Elena Rybakina winner with a brilliant baseline rescue before Kazakh nets.
Three set points... Gauff needs only one. Outstanding.
*Gauff 5-3 Rybakina
Coco Gauff has hit more winners and points receiving, while committing fewer unforced errors. She is ahead on just about every metric, emotional and statistical.
Elena Rybakina however gets a needed boost with a hold of serve. Gauff must serve for the set.
