NEW YORK -- There were few dull moments as Roger Federer took care of Nick Kyrgios in straight sets Saturday at the US Open and stayed on course for a potential quarterfinal matchup with Novak Djokovic, who also won in straight sets.
Federer, who fended off four break opportunities in a sluggish first set, eventually ran away with the match 6-4, 6-1, 7-5 to reach the fourth round for the 17th time in 18 attempts.
The world No. 2 hit 51 winners, none more specular than his running flick shot around the net post late in the third set that sent the fans into a frenzy. Even Kyrgios stopped to appreciate the moment.
"Yeah, it was unbelievable," Kyrgios said afterward. "I'm probably going to place it on Instagram."
Federer later explained that it was one of the more "unique" shots in his career.
"Like I explained on court, you don't get an opportunity to hit around the net post very often because in practice, you, I mean, you can't really train them," he said. "The net is out further, and the court is more narrow, so for a shot like this to happen in a practice, you will be running into a fence, and you will hit it into the net.
"I have hit a few throughout my career, and sure, they are always fun. ... As you're hitting it, you're like, 'Oh, I can just shove it down the line and just flat.' That's what happened today."
Early on, tensions ran high for Kyrgios, who was overheard berating his camp, which appeared to be encouraging him to get in his first serve.
"Say something else, say something else .... move your feet or something ... first serve, first serve, always first f---ing serve," Kyrgios said, glaring at his camp. "Of course I am trying to get in the serve."
Afterward, Kyrgios said he was frustrated about not capitalizing on his chances.
"You know, got to the business end of the first set, crucial moment," Kyrgios said. "Played a terrible service game. Didn't make any first serves. Just it was tough. I knew how important that first set was."
In the second set, Kyrgios yelled, "I need to hire a coach!"
When asked about it later, Kyrgios laughed it off, denying that he said it. He said not having a coach had nothing to do with his performance Saturday.
"At 3-all, love-40 [in the first set], I take one of those points, the match is wide open," Kyrgios said. "He's not going to play as well as he did towards the end of the first set or into the second set. Doesn't take a rocket scientist to figure that out."
On Monday, Federer will take on Australian John Millman for a spot in the quarterfinals.
Djokovic was efficient in a 6-2, 6-3, 6-3 victory over No. 26 Richard Gasquet. He saved all five break points he faced and is now 13-1 for his career against Gasquet, including 11 wins in a row.
Djokovic has won two of his 13 Grand Slam titles at Flushing Meadows. He'll face 68th-ranked Joao Sousa of Portugal in the fourth round Monday. Win that, and a meeting with Federer could be next.
"Look, I know that I'm the clear favorite in the match,'' Djokovic said. "At the same time I will try to maintain the level of focus and performance and level of tennis that I've had today.''
Also Saturday, two seeded men lost in the afternoon to unseeded opponents: No. 4 Alexander Zverev and No. 17 Lucas Pouille. Zverev has never made the fourth round in visits to New York after being beaten 6-7 (1), 6-4, 6-1, 6-3 by Philipp Kohlschreiber in an all-German matchup, while Joao Sousa defeated Pouille 7-6 (5), 4-6, 7-6 (4), 7-6 (5).
Kohlschreiber next meets 2014 runner-up Kei Nishikori, who got past No. 13 Diego Schwartzman 6-4, 6-4, 5-7, 6-1.
Information from The Associated Press was used in this report.