Eight-time men's champion Roger Federer and seven-time women's champion Serena Williams moved into the third round at Wimbledon.
Defending women's champion Angelique Kerber went out in the second.
Federer advanced as expected on Thursday, beating wild-card entry Jay Clarke 6-1, 7-6 (3), 6-2 on No. 1 Court. Williams had a bit of a tougher time at the same stadium, needing to come back to beat Slovenian qualifier Kaja Juvan 2-6, 6-2, 6-4.
But unseeded American Lauren Davis pulled off the unexpected, defeating Kerber 2-6, 6-2, 6-1 on No. 2 Court.
"I told myself you're strong, you can do it, you belong here," said Davis, who only entered the tournament as a lucky loser.
Kerber beat Williams in last year's final. Federer won his eighth title at the All England Club in 2017 and was eliminated in the quarterfinals last year.
Despite his pedigree at Wimbledon, Federer played his British opponent on the second biggest court on the grounds instead of his usual spot on Centre Court.
"I really enjoyed myself on Court 1 today with the roof," Federer said. "I couldn't really tell if it was Centre Court or Court 1, actually."
Williams played her match with good friend Meghan, the Duchess of Sussex, watching from the stands. She had a chance to serve out the match at 5-2 in the third but was broken. She made no mistakes on her second attempt, however, converting her first match point with an ace.
"I play best when I'm down sometimes," Williams said. "I'm just a fighter and never give up."
If the pressure is getting to Ash Barty at Wimbledon, she's doing a great job of hiding it.
The top-ranked Australian came into the grass-court Grand Slam tournament after winning the French Open and a Wimbledon warm-up event in Birmingham. And she's now won two in a row at the All England Club to reach the third round and stretch her winning streak to 14 straight.
Barty beat Alison Van Uytvanck 6-1, 6-3, needing only 55 minutes on No. 2 Court to advance. And it could have been even quicker but she failed to serve out the match at 5-2 in the second set — the only time she was broken.
"Pretty sharp right from the start," the top-seeded Barty said. "I was able to implement what I wanted to right away and put the pressure straight back on her."
Barty is playing her first tournament as No. 1 but has never been past the third round at Wimbledon. She will next face Harriet Dart, a British wild-card entry making her second appearance at Wimbledon.
Two-time Wimbledon champion Petra Kvitova, No. 9 Sloane Stephens and No. 15 Wang Qiang also advanced to third round. Kvitova beat Kristina Mladenovic 7-5, 6-2, Stephens defeated Wang Yafan 6-0, 6-2, and Wang ousted Tamara Zidansek 6-1, 6-2.
Sam Querrey, a Wimbledon semifinalist in 2017, reached the third round in the men's draw. The unseeded American defeated Andrey Rublev 6-3, 6-2, 6-3.
Later, all eyes will be on the marquee matchup between Rafael Nadal and Nick Kyrgios.
It is a rematch from 2014, when a 19-year-old Kyrgios upset then-No. 1 Nadal at the All England Club.
Also, Andy Murray was making his debut at this year's tournament, playing men's doubles with Pierre-Hugues Herbert against Marius Copil and Ugo Humbert.