Defending champion and second seed Petra Kvitova has crashed out of Wimbledon, leaving just four of the top 10 women left in the tournament.

The Czech, who was also champion in 2011, lost 3-6 7-5 6-4 to veteran campaigner Jelena Jankovic who goes on to play 2012 runner-up Agnieszka Radwanska for a spot in the quarter-finals.

Kvitova’s earliest loss at the All England Club since 2009 leaves just Serena Williams, Maria Sharapova, Caroline Wozniacki and Lucie Safarova as the last remaining top 10 seeds going into the second week.

“I don’t know what to say. I’m overwhelmed. I’m so excited. My heart is still pumping,” said 30-year-old Jankovic who has reached the last 16 for the fifth time.

Kvitova has now bowed out of the last four grand slams before the quarter-finals.

“I said many times that it’s something really special to be Wimbledon champion. That’s why I’m playing tennis. I was the lucky to win it here,” Kvitova said.

“So it’s not great to lose in the third round. Not to be in the second week of the favourite tournament for me is really sad.

“It’s not easy to go away. I think it’s going to take me few days, few weeks maybe (to recover).

“But that’s how it is. It’s tennis. I’m still human. I’m not a robot.”

Kvitova plans to get away from tennis for a while as she comes to terms with the end of her Wimbledon reign.

But the downhearted Kvitova conceded that even time with her nearest and dearest wouldn’t be an immediate salve for her wounded pride.

“First of all, I’m coming home to see my family and friends,” she said. “But I’m just probably going to need some time.”

Meanwhile, Danish fifth seed Caroline Wozniacki reached the last 16 for the fourth time with a comfortable 6-2, 6-2 win over Italy’s Camila Giorgi.

The former world number one will face Spain’s Garbine Muguruza after the 20th seed shocked 2012 semi-finalist Angelique Kerber 7-6 (14-12) 1-6 6-2.

Muguruza, who made the French Open quarter-finals this year, saved nine set points in the opener on her way to a first appearance in the second week at Wimbledon.

Romania’s Monica Niculescu also made the last 16 for the first time, beating Czech world number 134 Kristyna Plskova 6-3 7-5.

She will face Switzerland’s Timea Bacsinszky who put out 2013 runner-up Sabine Lisicki 6-3 6-2 to book a spot in the last 16.

Belarus qualifier Olga Govortsova also reached the fourth round for the first time with a 7-6 (7-4) 6-3 over Magdalana Rybarikova and next tackles American 21st seed Madison Keys, a semi-finalist in Australia this year.