“I’m very happy with the level of play and the atmosphere,” Federer said in an on-court interview.
Meanwhile, Serena Williams needed a medical time out in the second set of her 6-3, 6-4 win over Petra Martic to get treatment on her right ankle but recovered to advance to the quarter-finals.
Williams has dealt with various health issues all season, including one that ended her stay at the Australian Open.
Williams immediately asked for a trainer, who added tape to her lower right leg and foot during a medical timeout at the ensuing changeover midway through the second set against Martic.
‘‘I just rolled it. I don’t know why,’’ said Williams, who will face No.18 Wang Qiang of China next. ‘‘I was volleying and it just went over, so that was a little frustrating.
‘‘It’s been a rough year with injuries,’’ said the 37-year-old, who owns six US Open titles and 23 grand slam singles trophies in all, ‘‘so I thought, ’Oh, no, not again!’’’
The scene brought back memories of Williams’ Australian Open quarter-final in January against Karolina Pliskova. Williams was way ahead – holding a match point at 5-1, 40-30 in the third set – when she turned her left ankle awkwardly.
From there, Williams was no longer, well, Williams, dropping every point she served the rest of the way. She failed to convert four match points in all that day, ceded six games in a row and lost 7-5 in the third. That time, Williams didn’t call for a trainer, which surprised many. This time she didn’t make that mistake.
Williams has not managed to complete a non-slam tournament in 2019, withdrawing from each with one ailment or another, including a viral illness, a hurt left knee and, most recently, back spasms.