Second seed Kim Clijsters is looking forward to a US Open semi-final against Venus Williams but she will have to improve on an error-strewn display in the last eight against Sam Stosur.
Clijsters was sorely out of form for much of her 6-4 5-7 6-3 win over fifth seed Stosur on Arthur Ashe court, but found just enough composure to emerge victorious for the 19th time in a row at Flushing Meadows.
There were 15 breaks of serve in a match littered with errors from both players but as the game reached its climax, the Belgian finally found some form to hold off her Australian opponent, who should have cashed in on Clijsters' sluggish opening.
Third seed Williams had it slightly better, a 7-6 (7-5) 6-4 winner against Francesca Schiavone, and the pair will now meet for a place in the final.
Clijsters said: "It's been really tough to get used to the weather conditions here, every match has just been a battle and you have to try and beat it.
"I tried to be a little more aggressive in the final set but my serve wasn't going as well as I'd like it to. I ended up winning though and that's all that matters.
"Venus is a great competitor and she's playing some great tennis. She's American too and that will be a fun match to play.
"I've had some great matches against Venus and Serena, it'll be a great challenge and I'm excited to be in another semi."
Clijsters started particularly poorly but came from a break behind to sneak the first set.
She could not repeat the trick in the second as Stosur showed some real resilience but following six consecutive breaks of serve in the decider, Clijsters finally got her game in order, stringing together three consecutive games to take a 6-3 triumph.
Williams was in better touch, though not her formidable best and needed a tie-break to take the opening set against sixth seed and French Open champion Schiavone.
A service break put her 4-1 up in the second but although Schiavone returned gutsily to get back in contention, Williams broke again to seal the win.
Williams admitted she was unsure what effect the strong wind conditions would have on the match.
"When I walked out there, I couldn't even warm up my serve because the wind was blowing my toss," she said.
"I thought 'Oh, my god, what are we in for today?' I'm a strong player and I hit hard, but I felt like I had nothing.
"So it was challenging. I don't think either of us were able to play our exact normal game because it was just hard to make a choice in the wind.
"I think you end up playing a little safer, more toward the centre of the court."
Reflecting on her exit, Schiavone was a picture of frustration.
Despite being winless against Williams in seven meetings, she felt she missed an opportunity tonight.
"Yes, I'm disappointed, because I had the chance and the quality to beat her," said the Italian. "I think I lost this match a little bit more than she won it."