LONDON — Serena Williams earned a decent day's rest on the middle Sunday at Wimbledon as Jo-Wilfried Tsonga had to work overtime — 19-17 in the fifth set — in another marathon involving John Isner.
Williams, the defending women's champion and six-time winner, overwhelmed Annika Beck 6-3, 6-0 in just 51 minutes on Centre Court early Sunday afternoon, advancing to the fourth round with her 300th career Grand Slam match win.
Williams, who compiled a 25-2 edge in winners, wasn't aware of the 300-win milestone until she was asked about it in a post-match interview.
"Was it? Cool. Oh, nice," she said with a laugh. "I had no idea. That's awesome, right? That's good, right? I think that's a lot of matches."
Williams' latest win breaks a tie at 299 wins with Chris Evert. She now ranks second in the Open era behind Martina Navratilova, who went 306-49.
For only the fourth time in Wimbledon's 139-year history, play was scheduled on the middle Sunday, which is the traditional rest day, because of rain delays in the first week that caused a backlog of matches. All 22,000 tickets were snapped up in 27 minutes when they went on sale online on Saturday.
After falling an early break behind at 2-1, Williams won 11 of the last 12 games and 24 of the second set's 28 points.
"I still want to get out to a little bit of a faster start," Williams said. "But I was really focused and calm today."
While Williams played just 15 games in under an hour, Tsonga and Isner needed 44 games and 2 hours, 33 minutes to complete the final two sets of their suspended third-round match. The final set featured 36 games and lasted 2 hours, 8 minutes.
"It's good to be alive," said Tsonga, who saved a match point at 16-15 in the fifth before overcoming the American 6-7 (3), 3-6, 7-6 (5), 6-2, 19-17.
Isner led two sets to one when play suspended because of darkness on Saturday. The match lasted a total of 4 hours, 24 minutes on Court 2.
That's still modest compared to Isner's win over France's Nicolas Mahut six years ago. He prevailed 70-68 in the final set of the longest match in tennis history, which lasted more than 11 hours over three days in the first round.
Tsonga, a Frenchman seeded No. 12, got the only break of Sunday's fifth set to go ahead 18-17. He then served out the match at 15, hitting a running backhand cross-court volley into the open court to close it out. He hopped up and down and swung both arms in celebration as the crowd erupted.
It was Tsonga's 103rd match win in a Grand Slam, putting him in a tie with Jean Borotra at the top of the list of French players with the most victories in majors.
Tsonga's next opponent will be countryman and No. 7 Richard Gasquet, who downed Albert Ramos-Vinolas of Spain, 2-6, 7-6 (5), 6-2, 6-3. Tsonga and Gasquet have both reached the semifinals here twice.
Another Frenchman, No. 32 Lucas Pouille, ended the Grand Slam comeback of Juan Martin del Potro, beating the Argentine 6-7 (4), 7-6 (6), 7-5, 6-1. The 22-year-old Pouille had never won a tour-level match on grass until this tournament. Del Potro was making his first appearance at Wimbledon since 2013 after a series of surgeries on his left wrist.
Nick Kyrgios, an Australian seeded No. 15, set up a marquee fourth-round matchup against No. 2 Andy Murray, defeating Feliciano Lopez 6-3, 6-7 (2), 6-3, 6-4. Kyrgios, who served out the match after receiving a time delay warning, made it to the quarterfinals as a wild card in 2014.
Williams will next face No. 13 Svetlana Kuznetsova, who came from behind to beat No. 22 Sloane Stephens 6-7 (1), 6-2, 8-6 to reach the fourth round at Wimbledon for the first time since 2008.
Williams has a 9-3 career record against Kuznetsova, but the Russian beat her this year on hard courts in Miami. Kuznetsova, a two-time Grand Slam champion, has reached the quarterfinals here three times, but the last time was back in 2007.
CoCo Vandeweghe, making a strong run at Wimbledon for the second year in a row, beat No. 7 Roberta Vinci of Italy 6-3, 6-4 in the first match on Centre Court. The 27th-seeded American advanced to the quarterfinals here last year before losing to Maria Sharapova in three sets.
Her fourth-round opponent will be 23rd-seed Anastasia Pavlyuchenkova of Russia, who downed No. 11 Timea Bacsinszky of Switzerland 6-3, 6-2.
Also advancing was 50th-ranked Elena Vesnina, who beat 225th-ranked American qualifier Julia Boserup 7-5, 7-5.