LONDON - The women's singles defending champion Marketa Vondrousova was ousted from the Wimbledon Championships after losing to Jessica Maneiro in the opening round on Tuesday.

One year ago, an unseeded Vondrousova flew high here to clinch her first Grand Slam title. But a return to the Centre Court of the All England Club this year was ended with a painful loss for the 25-year-old Czech.

"It's tough to go out defending the title," said Vondrousova after losing to the 21-year-old Maneiro from Spain 6-4, 6-2. "I was really nervous from the morning. She was playing good tennis while I wasn't at my best."

Maneiro, who had never won a Grand Slam main draw match before, will meet compatriot Cristina Bucsa in the second round.

"Marketa is one of the best players in the world. She won here last year, so I had no pressure, just had to enjoy myself, enjoy this tournament. I was just trying to be free playing, and I did it, so I'm happy for that," said the world No 83 Maneiro.

The men's singles sixth seed Andrey Rublev also suffered an early exit as the Russian was beaten by Argentina's Francesco Comesana 6-4, 5-7, 6-2 and 7-6(5).

The women's singles world No.1 Iga Swiatek and the 24-time Grand Slam champion Novak Djokovic both went through breezily. Swiatek dominated her match against Sofia Kenin to win in straight sets while Djokovic needed no more than two hours to defeat qualifier Via Kopriva 6-1, 6-2, 6-2.

"I didn't know how I'm going to feel on the court and how knee is going to hold up. But very happy with the way I felt, with the way I played, with the way I moved. For an opening match, I couldn't ask for a better start," said Djokovic who underwent a knee surgery about three weeks ago.