LONDON — Petra Kvitova avoided becoming the latest former champion to be knocked out in the first week at Wimbledon, rallying from a break down in the final set to beat Ekaterina Makarova of Russia 6-3, 2-6, 6-3 on Saturday.
Last year's runner-up, Agnieszka Radwanska, also advanced, while Centre Court featured another upset when ninth-seeded Richard Gasquet lost to Bernard Tomic, the Australian whose father has been barred from tournaments because of an assault case.
Later Saturday, top-ranked Novak Djokovic and Serena Williams were set to play their third-round matches, also looking to avoid further upsets after Roger Federer, Rafael Nadal and Maria Sharapova were eliminated early.
Kvitova's third-round match was halted on Friday with Makarova up 2-1 in the third set, but Kvitova broke right back when play resumed and won the next two games. After losing her own serve, the Czech broke again for 5-3 and converted her third match point with a forehand winner.
"I should go for every point and play my game," Kvitova said. "I played quite aggressively. That was the key."
Kvitova won Wimbledon in 2011 but hasn't come close to those heights since, and has slipped from second to eighth in the rankings. She has a good chance of reaching her second final at the All England Club, however, having seen second-seeded Victoria Azarenka and Sharapova exit on her side of the draw.
To have a chance at another title, though, Kvitova said her consistency has to improve.
"I have dropped off a little bit," she said. "I'm always a little bit up and down, but I hope it will be more up than down."
Radwanska held off a hard-serving performance by American teenager Madison Keys to win 7-5, 4-6, 6-3. Radwanska needed five match points before sealing the victory when Keys, who finished with 15 aces, sent a return wide.
Tomic, who in 2011 as an 18-year-old qualifier became the youngest Wimbledon quarterfinalist since Boris Becker in 1985, beat Gasquet 7-6 (7), 5-7, 7-5, 7-6 (5).
Tomic's father and coach, John, is accused of head-butting his son's training partner before a tournament in Madrid and has been barred from even buying a ticket to Wimbledon. However, Tomic said he's still getting advice and help from his father.
"He's helping me at this tournament," Tomic said. "I'm not doing it on my own. My dad is still involved. That's why I've gotten to where I am in this tournament."
Former runner-up Tomas Berdych also advanced, beating Kevin Anderson of South Africa 3-6, 6-3, 6-4, 7-5. He was joined by No. 8 Juan Martin del Potro, who overcame a scary late fall to beat Grega Zemlja of Slovenia 7-5, 7-6 (3), 6-0.
Del Potro hurt his left leg when chasing down a drop shot in the third set, skidding awkwardly on the grass and tumbling face first. He received treatment after taking a 4-0 lead and took a medical timeout after the next game, and returned to break Zemlja again to clinch the win.
Because of rain over the last two days, Wimbledon organizers were playing a bit of catch-up with the schedule on Saturday, ahead of Sunday's rest day.
Among other matches that had been postponed, No. 20 Mikhail Youzhny of Russia beat Viktor Troicki of Serbia 6-3, 6-4, 7-5 to set up a fourth-round meeting with second-seeded Andy Murray.
No. 23 Andreas Seppi of Italy kept up his perfect record in five-set matches in 2013, winning his seventh straight by defeating 12th-seeded Kei Nishikori of Japan 3-6, 6-2, 6-7 (4), 6-1, 6-4. Seppi also beat Denis Istomin in five sets in the first round, and won two five-setters each at this year's Australian Open and French Open. He also rallied from two sets down in Davis Cup this year.
As is traditional on the middle Saturday of the tournament, the Royal Box on Centre Court was filled with invited sports stars, this year mainly British gold-medal winners from the London Olympics. Among those getting the biggest ovation from the crowd were cyclists Chris Hoy and Victoria Pendleton, as well as Murray, who donned a suit and tie to make a brief appearance in the box to celebrate his singles gold medal won on Centre Court.
Laura Robson then made it another good day for the home crowd when she became the first British woman since Sam Smith in 1998 to reach the fourth round.
Helped by a crucial overturned call, Robson rallied from a set and a break down to beat Marina Erakovic of New Zealand 1-6, 7-5, 6-3.
Erakovic served for the match in the second set, only for Robson to break back. Having then earned a set point at 6-5, Robson barely got a return back that looped high and just caught the edge of the line, but was called out before Erakovic could smack a winner. Robson successfully challenged the call and the point was replayed, with Erakovic double-faulting to hand her opponent the set.
Robson jumped out to 4-0 in the decider, and clinched the victory with a forehand winner.
"I was getting my butt kicked basically (in the first set)," Robson said. "So I just thought, just going to try as best as I can, work as hard as possible and just stick with it until she starts to get nervous, which is what happened."
Igor Sijsling of Netherlands retired against Croatia's Ivan Dodig when trailing 6-0, 6-1, 1-0, the 13th retirement or walkover of the tournament. That equals a Wimbledon record from 2008.