London (AFP) - Defending champion Barbora Krejcikova battled back from a set down to win her Wimbledon opener on Tuesday as men’s top seed Jannik Sinner barely broke sweat in the searing London heat.

There were high-profile casualties on day two at the All England Club as men’s third seed Alexander Zverev and women’s third seed Jessica Pegula crashed out of the grass-court Grand Slam.

Novak Djokovic was kept waiting until the evening to make his return to Centre Court as he targets a record 25th major.

Krejcikova came to Wimbledon with just six matches under her belt this year and was in grave danger after being outplayed by Philippines star Alexandra Eala in the first set.

But the two-time Grand Slam champion regrouped, cut her error count drastically and lost just three more games as she completed a 3-6, 6-2, 6-1 win.

Krejcikova has endured a difficult time since defeating Italy’s Jasmine Paolini in the final last year.

The 29-year-old was out of action this season until May after suffering a back injury and lost in the second round of the recent French Open.

Krejcikova pulled out of last week’s Eastbourne Open before the quarter-finals with a thigh problem.

“I was in a lot of pain in my back and I didn’t really know how my career was going to go,” she said. “I’m super happy and super excited that I can be here and that I can play on such a great court.

“I was really, really excited for this day and before the match I was really counting every minute to the time when the match is coming up.”

Men’s world number one Sinner brushed aside fellow Italian Luca Nardi on Court One with the minimum of fuss.

Unfazed by the scorching conditions, the three-time Grand Slam champion sealed a 6-4, 6-3, 6-0 win in just one hour and 48 minutes.

“I’m very happy to come back here to such a special place for me,” he said. “Playing an Italian is very unfortunate but one has to go through and luckily it was me.”

Sinner has won three of the past six majors but the 23-year-old blew a two-set lead and wasted three match points against Carlos Alcaraz at last month’s French Open final.

- Djokovic record bid -

Djokovic starts his Wimbledon campaign against France’s Alexandre Muller, ranked 41 in the world.

The sixth-seeded Serb, who has been in every Wimbledon final since 2018, has only played Muller once, dropping just five games during his march to the 2023 US Open title.

But at 38 he knows time is running out as Alcaraz and Sinner establish a stranglehold at the top of the men’s game.

Djokovic has been tied with long-retired Margaret Court on 24 Grand Slam singles titles since 2023 but he believes his most realistic hope of a historic 25th win lies at the All England Club.

The veteran, who has lost the past two Wimbledon finals to Alcaraz, has the added incentive of pulling level with the retired Roger Federer, who won a record eight men’s titles at the All England Club.

Former US Open runner-up Pegula suffered a shock defeat against Italy’s Elisabetta Cocciaretto, losing 6-2, 6-3 in just 58 minutes.

Pegula was followed out of the tournament by Olympic champion Zheng Qinwen, the Chinese fifth seed a surprise 7-5, 4-6, 6-1 loser against world number 81 Katerina Siniakova.

Five-time Grand Slam winner Iga Swiatek swatted aside Russia’s Polina Kudermetova 7-5, 6-1 and second seed Coco Gauff, fresh from her French Open triumph, prepared to take on Ukraine’s Dayana Yastremska.

Two-time Wimbledon champion Petra Kvitova, handed a wildcard to compete, lost 6-3, 6-1 in an emotional farewell appearance against US 10th seed Emma Navarro.

In the men’s draw, Zverev suffered his earliest Grand Slam exit since 2019, dumped out by France’s Arthur Rinderknech after a five-set marathon in a match that started on Monday evening.

Fifth seed Taylor Fritz completed a five-set win against France’s Giovanni Mpetshi Perricard in a match that also started on day one.

British fourth seed Jack Draper progressed when Argentina’s Sebastian Baez retired with the score at 6-2, 6-2, 2-1.