Roger Federer, of Switzerland, returns to David Goffin, of Belgium, during the fourth round of the US Open tennis championships Sunday, Sept. 1, 2019, in New York. (AP Photo/Sarah Stier)

NEW YORK (AP) — At his very best, Roger Federer can make even good players look lost on a tennis court.

“You don’t know why you’re missing everything. Easy balls,” David Goffin said. “All of a sudden he’s playing well.”

That’s the way Federer looked when won five straight U.S. Open titles, and the way he’s rolling into the quarterfinals now.

Federer reached the final eight at Flushing Meadows for the 13th time Sunday by routing Goffin 6-2, 6-2, 6-0. After slow starts in the first two rounds, he has conceded just nine games over his last two matches.

“In a fourth round like this, if you can keep it nice, short, simple, you have to take them,” Federer said.

A year after getting knocked out in the fourth round, the five-time champion showed there would be no repeat of that. He rebounded from an early break to win the final five games of the first set and never let up from there, finishing it off with a backhand down the line in a third set that lasted just 21 minutes.

Federer tied Andre Agassi for the second-most quarterfinal appearances at the U.S. Open, trailing only Jimmy Connors’ 17. He had been surprisingly stopped a round short in 2018 by John Millman, preventing what would have been a matchup with eventual champion Novak Djokovic.

Federer lost the opening set in each of his first two matches for the first time in his 19 U.S. Open appearances, but the No. 3 seed has been pretty perfect since while playing the first match of the day in Arthur Ashe Stadium. The 15th-seeded Goffin broke for a 2-1 lead but that was about his last highlight, as Federer amassed a 35-8 advantage in winners and converted nine of his 10 break-point chances.

That followed his 6-2, 6-2, 6-1 rout of Dan Evans in the third round, making it consecutive performances that looked like they belonged in the 20-time Grand Slam champion’s highlight reel.

“I feel like I’ve had many good finals or moments where I just, like, I’m just not going to lose this match, I feel too good today,” Federer said.

He will face Grigor Dimitrov, who swept past Alex de Minaur 7-5, 6-3, 6-4 to reach his first U.S. Open quarterfinal.

Earlier Sunday, Ash Barty was knocked out by Wang Qiang, leaving only one of this year’s major champions in the women’s tournament.

The No. 2 seed and French Open champion was beaten 6-2, 6-4 by Wang, who became the first Chinese woman to reach a U.S. Open quarterfinal since Peng Shuai reached the semis at Flushing Meadows in 2014.

With Wimbledon champion Simona Halep already out in the second round, only top-ranked Naomi Osaka remains among the women who won a Grand Slam tournament this year. The defending U.S. Open champion also won the Australian Open in January.

No. 3 Karolina Pliskova is out, too, beaten by 16th-seeded Johanna Konta in three sets.

Osaka, who recently regained the No. 1 ranking that Barty held earlier this summer, was off Sunday after beating 15-year-old American Coco Gauff on Saturday night to reach the round of 16.

Barty won her first Grand Slam in Paris in June and reached the round of 16 in all four majors this season.

“Just because we’ve had a tough hour and a half on the court, it doesn’t reflect on the year that I’ve had or the couple of weeks I’ve had here in New York,” Barty said.

Wang, meanwhile, is into the quarterfinals of a Grand Slam tournament for the first time in her 21st try and could meet Serena Williams, who was playing Petra Martic later Sunday in a fourth-round match.

Daniil Medvedev then follows them onto Louis Armstrong Stadium, where the No. 5 seed was loudly booed during and after his third-round victory Friday.