After slow starts in his first two US Open matches, Roger Federer took his game up a notch on Friday with a stress-free 6-2, 6-2, 6-1, win over Briton Daniel Evans to reach the round of 16 in New York. The Swiss great was brimming with confidence from the start, taking advantage of the speedy hardcourts under the open roof at Arthur Ashe Stadium on a warm and sunny day. Federer, who is seeking his sixth U.S. Open title, rifled 48 winners and 10 aces to see off the overmatched Evans, who is now 0-3 lifetime against the 38-year-old. Federer has had limited court time since his epic defeat to Novak Djokovic at the Wimbledon final in July but appeared to shake off any remaining rust with the win. "I really enjoyed myself today. Beautiful sky and you guys out here also helped," he said in an on-court interview in front of an adoring crowd. Next up for third seeded Federer is a meeting with either Pablo Carreno Busta or David Goffin, and Federer said he would not underestimate either opponent. "They are both really quality baseliners," he said, adding that he expected the 15th seed Goffin to come out on top in his tie with the Spaniard. "I expect it to be tough, not like today anyway." Australia's Alex de Minaur knocked out 2014 US Open finalist Kei Nishikori in Friday's third round of the US Open to collect his first victory over a top-10 player. The 20-year-old Aussie, ranked 38th, advanced 6-2, 6-4, 2-6, 6-3 in just under three hours. De Minaur will face Bulgaria's Grigor Dimitrov or Polish lucky loser Kamil Majchrzak in the last 16. Czech third seed Karolina Pliskova, chasing her first Grand Slam title, advanced to the fourth round of the US Open on Friday by outlasting Tunisia's Ons Jabeur 6-1, 4-6, 6-4. Pliskova, the 2016 US Open runner-up who could finish the fortnight as world No. 1, booked a spot in the last 16 against either British 16th seed Johanna Konta or China's 33rd-seeded Zhang Shuai. After taking the first set in 26 minutes, Pliskova broke to open the second. Jabeur, ranked 62nd, had her right knee retaped and battled back to break Pliskova three times in the second set, the last on a forehand winner to force a third set. Pliskova broke to start the third set and seized another in the fifth game on an errant Jabeur forehand before advancing on a backhand winner after two hours and eight minutes. "She improved the game a lot in the second set, she hit a couple unbelievable shots and got into her rhythm," Pliskova said. "Especially had to serve well. Was able to hit a couple aces in the third set which really helped. Physically it was quite a tough battle. It was important to win so it doesn't matter how I feel. So pleased to be through." Pliskova, 27, is battling top-ranked defending champion Naomi Osaka of Japan and Australia's second-ranked Ashleigh Barty, the French Open winner, for the world No. 1 spot. Barty, who faces Greek 30th seed Maria Sakkari later, has the inside track because Osaka has so many points to defend. Osaka must win the title to have any chance at staying on top while Pliskova must reach at least the semifinals. Former world No. 1 Serena Williams resumes her quest for a 24th career Grand Slam title to equal Margaret Court's all-time record when she meets 44th-ranked Czech Karolina Muchova in a third round matchup at Arthur Ashe Stadium. The 37-year-old American, six times a US Open champion, has been a runner-up in three of the past five Slams, falling to Osaka in last year's US Open final. She last won a Slam crown at the 2017 Australian Open while pregnant and hasn't won the US Open title since 2014. US Open fines Spain's Suarez Navarro $40K for poor effort Spain's Carla Suarez Navarro has been fined $40,000 by the US Open for lack of effort in her first-round match against Hungarian qualifier Timea Babos, tournament referee Soeren Friemel said. Suarez Navarro, a US Open quarter-finalist last year, matching her best Grand Slam run, retired at the end of the first set with a lower back injury. The 30-year-old, who reached the fourth round last month at Wimbledon, won her only WTA titles at the 2014 Portugal Open and 2016 Qatar Open. Grand Slam rules outline a code of conduct for performances in first-round matches, with players expected to perform to "a professional standard." "After reviewing reports from the medical staff and the Grand Slam supervisors, the determination was made that Carla Suarez Navarro did not perform to the required professional standards," Friemel said in a statement. She could have been fined up to the full $58,000 she received for a first-round loss at the year's final Grand Slam event. Del Potro targets October return from knee injury Former US Open champion Juan Martin del Potro said Friday he expects to make his return from a broken right kneecap in October at the ATP tournament in Stockholm. Del Potro, the 2009 champion from Argentina, has not played since slipping and hurting his knee on the grass in the Wimbledon tune-up at Queen's in June. He underwent surgery before returning home to begin his recovery. "I'm very happy to tell you that I'll play in Stockholm and Vienna in October. These two tournaments are very special to me, as I had the chance to win both of them," Del Potro tweeted. The injury-plagued 30-year-old was forced to miss this year's US Open after finishing runner-up to Novak Djokovic in the 2018 final. He first fractured his kneecap last October when he fell during a match at the Shanghai Masters. — Agencies