LONDON, July 3 (Reuters) - Fifth seed Stan Wawrinka suffered a first-round exit in the biggest upset of day one at Wimbledon on Monday.
The 32-year-old Swiss, who was struggling with a knee injury, fell to Russia's Wimbledon debutant Daniil Medvedev 6-4 3-6 6-4 6-1 on Centre Court.
Britian's defending champion Andy Murray had opened proceedings on the main show court by shrugging off a sore hip to launch his campaign in style, beating Kazakhstan's Alexander Bublik 6-1 6-4 6-2.
Murray, the world number one, hit 29 winners to wrap up the match in one hour 44 minutes. He will meet German Dustin Brown in the next round.
French Open champion Rafael Nadal also raced to a straight sets win over Australia John Millman but 20th seed Nick Kyrgios failed to reach the second round after retiring with a hip injury.
The talented 22-year-old called for the physio but packed up after losing the first two sets to Frenchman Pierre-Hugues Herbert 6-3 6-4.
In the women's draw, five-time Wimbledon champion Venus Williams came through a tricky first-round test against Belgian Elise Mertens, emerging with a 7-6(7) 6-4 victory.
Twice champion Petra Kvitova of the Czech repubic opened her title bid with a 6-3 6-4 win over Sweden's Johanna Larsson, while French Open finalist Simona Halep beat Marina Erakovic 6-4 6-1 to book a second round spot.
There was also plenty to cheer for the home crowd with British number on Johanna Konta avenging her French Open first round defeat with a 6-2 6-2 win over Hsieh Su-Wei of Taiwan.
Konta's compatriot Heather Watson also reached round two, beating Belgium's Maryna Zanevska 6-1 7-6(5).
Highlights from day one of the Wimbledon championships on Monday (all times GMT):
- French Open champion Jelena Ostapenko booked her place in the second round with a 6-0 1-6 6-3 win over Aliaksandra Sasnovich of Belarus.
- Spaniard Carla Suarez Navarro beat former Wimbledon runner-up Eugenie Bouchard of Canada 1-6 6-1 6-1 to reach the second round.
- Former world number one Victoria Azarenka came back from a set down to claim a 3-6 6-2 6-1 victory over American teenager Catherine Bellis.
- Fifth seed Stan Wawrinka, a three-times grand slam champion, suffered a 6-4 3-6 6-4 6-1 defeat by Russian Daniil Medvedev in the first round at Wimbledon.
- Medvedev has reached a career high 49 in the world rankings after a semi-final appearance at Eastbourne last week.
- Britain's sixth seed Johanna Konta moved into the second round with a 6-2 6-2 win over Taiwan's Hsieh Su-Wei.
- The Briton fired 17 winners to avenge her French Open first round defeat by Hsieh.
- Konta's compatriot Heather Watson also progressed with a 6-1 7-6(5) win over Maryna Zanevska of Belgium.
- Seventh-seeded Croatian Marin Cilic was in fine form as he defeated German Philipp Kohlschreiber 6-4 6-2 6-3 in the opening round.
- Two-times winner Rafael Nadal was in sublime form on his way to a 6-1 6-4 6-2 win over John Millman of Australia.
- The Spaniard hit 17 forehand winners to seal the victory in an hour and 46 minutes.
- Two-time Wimbledon champion Petra Kvitova sealed a comfortable 6-3 6-4 win over Sweden's Johanna Larsson.
- World number 12 Kvitova was playing only her eighth match this year, having recently recovered from serious injuries to her playing hand sustained during a knife attack at her home last December.
- Fourth seed Elina Svitolina produced a fine display to see off Ashleigh Barty 7-5 7-6(8) in the first round.
- The 22-year-old reached her third consecutive third round at Wimbledon after making just 23 unforced errors during the match.
- Top seed Andy Murray begins his title defence with a 6-1 6-4 6-2 victory over Alexander Bublik in the opening round.
- World number one Murray was sharp at the net, winning 29 of 37 points to seal the victory.
- He will meet German Dustin Brown in the second round.
- Five-times Wimbledon champion Venus Williams booked a second-round spot with a 7-6(7) 6-4 win over Belgium's Elise Mertens.
- World number 54 Mertens was aggressive during the opening set but failed to control the mounting tally of unforced errors in the second, losing to the 37-year-old American in an hour and 39 minutes on Court One.
- Play resumed on all courts after a 30-minute rain interruption.
- Second seed Simona Halep raced through to the second round with a 6-4 6-1 victory over New Zealander Marina Erakovic.
- Romanian Halep, French Open runner-up last month, broke her opponent's serve five times during a match lasting an hour and 13 minutes.
- German Dustin Brown fought back to seal a 3-6 7-6(5) 6-4 6-4 victory over Joao Sousa of Portugal.
- Frenchman Jo-Wilfried Tsonga beat British wildcard Cameron Norrie 6-3 6-2 6-2 to book a spot in the second round.
- Tsonga, a two-times Wimbledon semi-finalist, recorded 30 winners on his way to a comfortable victory in an hour and 22 minutes.
- Australian Nick Kyrgios, the 20th seed and a former Wimbledon quarter-finalist, has retired with a hip injury after going 6-3 6-4 down to Frenchman Pierre-Hugues Herbert.
- The injury hampered Kyrgios' movement during the majority of the match as he committed 17 unforced errors.
- World number 70 Herbert reached the second round of Wimbledon for the third consecutive year.
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Compiled by Hardik Vyas in Bengaluru, editing by Ed Osmond