Novak Djokovic showed form and domination in his quarterfinal matchup, before the Serbian was given a shorter workout than expected at the US Open for the third time this year after Jo-Wilfried Tsonga retired through injury.
The world number one looked a lot more like his usual self, despite worries over an elbow injury, in leading 6-3, 6-2, before Tsonga decided he could not go on and retired owing to a knee injury.
This was the third time that an opponent has either withdrawn during a match or given Djokovic a walkover in this year's US Open. Jiri Vesely gave the defending champion a walkover in the second round, before Mikhail Youzhny retired after just six games in the third round.
Djokovic won't mind too much, though, because it keeps him fresh for a semifinal match against Gael Monfils, who beat Lucas Pouille, the conqueror of Rafael Nadal in the previous round, 6-4, 6-3, 6-3.
"I'm happy with my performance," Monfils told reporters. "I think it is never easy to play a quarterfinal against a French guy, you know. I think I handled it pretty good mentally and tennistically.
"I'm happy with that and where my game is. I see new or good stuff. Serve was a bit better. I have been saying I think to the French press that I could serve faster. I think I did it great. Still moving good. I'm very happy."
The two women's quarterfinals went according to plan, with Angelique Kerber, the No.2 seed, setting up a semifinal with Caroline Wozniacki, the former world number one. Kerber, in her quest to wrest the No.1 ranking from Serena Williams, Kerber has barely put a foot wrong in this US Open 2016, and the Australian Open champion was on the top of her game again, beating the finalist from last year Roberta Vinci 7-5, 6-0.
Wozniacki is another who has impressed in New York this year, and the Dane continued her top form in beating Anastasija Sevastova, who had previously knocked out the French Open champion Garbine Muguruza and No.13 seed Johanna Konta.
Indian interest at the US Open is over, after Sania Mirza and Barbora Strycova went down to the No.1 seeds Caroline Garcia and Kristina Mladenovic 7-6 (7-3), 6-1. It was a match that Sania and Stryvoca really should have won, or at the very least, taken to a third set. The Indo-Czech pair was up 4-1 and 5-3 in the opening set, but crumbled when a hold would have given them the lead.
From there, the No.1 seeds took full advantage, as Sania's first Grand Slam post the Martina Hingis split ended in disappointment.