Underdog Evans sets up Federer showdown
British number two Dan Evans beat 25th seed Lucas Pouille to earn himself a US Open meeting with Roger Federer.
The 29-year-old from Birmingham was an impressive 6-4 6-3 6-7 (4) 6-4 winner on Court 12 in New York.
Evans - who returned last year from a drugs ban - took advantage of a lacklustre display from Pouille, racing into a two-set lead and a break up in the third.
Frenchman Pouille belatedly found his range and broke Evans twice with the finish line in sight.
Evans hit back to level the set but then blew a 3-0 lead in the tie-break.
However, Evans finished the job in the fourth set to set up a third career clash with 20-time grand slam winner Federer.
The world number 58 has yet to take a set off the Swiss star, but he pushed him close in Australia earlier this year.
Sixth seed Alexander Zverev survived a second successive five-set marathon as he outlasted American Frances Tiafoe 6-3, 3-6, 6-2, 2-6, 6-3.
Germany's Zverev was taken the distance by Radu Albot in his opening match and 45th-ranked Tiafoe forced him into another decider before last year's ATP Finals champion battled through to round three to equal his best US Open run.
Novak Djokovic needed extensive treatment on a shoulder injury during his second-round win over Juan Ignacio Londero.
The defending champion and world number one came through a tough encounter in straight sets, 6-4 7-6 (3) 6-1, despite falling a double break behind in the second.
Ordinarily Djokovic is not a player who discloses any injury problems, but this one was difficult to hide and could hinder his title defence.
He admitted: "It was definitely affecting my serve and my backhand. I was definitely tested. This is something I have been carrying for quite a while now. It wasn't easy playing with the pain but you have to find a way."
Johanna Konta crushed Margarita Gasparyan in under an hour to advance to the third round.
Konta, who got her US Open campaign up and running with a battling three-set win over Daria Kasatkina, continued her solid form against another Russian in Gasparyan, winning comfortably 6-1 6-0 in 54 minutes.
The match was rescheduled from Wednesday after rain prevented any play on the outside courts, and Konta revelled in sunny conditions to dispatch the world No 61 in emphatic fashion.
Konta, the British No 1, took immediate control by using her powerful groundstrokes to break three times in a quick-fire first set.
Gasparyan crumbled under the mounting pressure coming from the other end of the court as 16th-seeded Konta produced more punishment to run away with the match, hitting 24 winners in a one-sided encounter on Court 5.
Serena Williams won her first US Open two years before Caty McNally was born - and she had to use all her experience to avoid crashing out to the 17-year-old.
Williams, the 23-time grand slam winner and last year's runner-up, found herself staring down the barrel of a major upset against her fellow American.
McNally, standing up to Williams' second serve, had the 37-year-old on the ropes when she took the first set.
But Williams dug deep in a dramatic late-night session to win 5-7 6-3 6-1 and progress to the third round.
"I think she really came out and played well, she showed no fear, she had nothing to lose and she played like it," said a relieved Williams.
Czech sixth seed Petra Kvitova, a two-time Wimbledon champion, was knocked out by Germany's 88th-ranked Andrea Petkovic 6-4, 6-4.
Petkovic, whose best US Open showing was a 2011 quarter-final run, reached the third round for the first time since 2015.
Top-ranked defending champion Naomi Osaka advanced to the third round by defeating Poland's 53rd-ranked Magda Linette 6-2, 6-4.