LONDON, July 4 (Xinhua) -- Fifth seed Stan Wawrinka suffered a shock defeat to Daniil Medvedev of Russia 6-4, 3-6, 6-4, 6-1 in the opening day's competition of the Wimbledon Championships on Monday.
Fourth seed Rafael Nadal beat the world No.137 John Millmain of Australia in a lopsided 6-1, 6-3, 6-2 match while Andy Murray begun the defence of his title with a 6-1, 6-4, 6-2 win over world No. 134 Alexander Bublik.
The 32-year-old Wawrinka, a three-time Grand Slam champion, needed ice on a knee injury between points as he became the biggest name to fall. World number 20 Nick Kyrgios was the other seeded player failing to reach round two, retiring because of a hip injury.
It was his Medvedv's first Grand Slam victory on his Wimbledon debut, and he dropped to his knees and kissed the green stuff.
"At 5-1, already I started thinking what I have to do after the match if I win it," the 21-year-old Medvedev said. "And I did it because it's my first Grand Slam win, it's at Wimbledon - my favourite tournament - I had to kiss the grass, I guess. Even though people do it when they win the slam, I did it when I win my first match at a slam."
"I had a really great grass court season," he said. "I knew that Stan had some problems at Queen's, he had only played on match on grass. I knew that I would have the chance if I played good and third and first set, I think I was playing amazing."
Medvedev has been maintaining good form this year. He reached the semifinals in Eastbourne last week and entered the quarterfinals at Queen's club. He has already secured a berth in the top 50 after the victory.
"I'm really happy," he said. "Wimbledon is my favourite Grand Slam. It was in my juniors and still is.
"One year ago I was 250th in the rankings and if someone said I would not only play on Centre but win I would say: 'You are joking!'"
Wawrinka has only reached two quarterfinals in his 13 appearances at Wimbledon.
"I wasn't feeling the way I wanted to feel but I played against a great player," said Wawrinka. "I had problems with the knee since Queen's. It is not something new but something I had in the past. Apparently grass is not the best surface for my knee and I need to figure out what I'm going to do and come back when I have no pain."
