LONDON • Stan Wawrinka endured a nightmarish start to his grass-court campaign, suffering a 7-6 (7-4), 7-5 first-round defeat by Spaniard Feliciano Lopez at the Queen's Club yesterday.
The second seed, bidding to complete a career Grand Slam at Wimbledon next month, also appeared to hurt his left knee during the first set, reported Eurosport.
The French Open finalist struggled to adjust to grass in his first match since losing to Rafael Nadal at Roland Garros.
In contrast, Lopez continued his fine form on the quicker surface, having made the Stuttgart Open final on Sunday before losing to Frenchman Lucas Pouille.
"I came here with a lot of confidence," Lopez told the BBC after progressing in 90 minutes. "I knew it was going to be tough against Stan so this was a great win for me."
Swiss Wawrinka, who has never gone beyond the Wimbledon quarter-finals, was the second big scalp taken yesterday.
Milos Raonic's Wimbledon preparations also suffered a major setback as the world No. 6 crashed to Australian wildcard Thanasi Kokkinakis 7-6 (7-5), 7-6 (10-8) in his opener.
The Canadian came agonisingly close to a golden summer on grass last year when he reached the Queen's and Wimbledon finals, only to lose to Andy Murray on both occasions.
However, his hopes of warming up for Wimbledon with another strong showing at Queen's were wrecked by Kokkinakis' stunning triumph on a baking hot afternoon in west London.
Kokkinakis needed a wild card from the tournament organisers to make the Queen's main draw after his ranking plunged to No. 698 following injuries to his shoulder and abdomen.
Finally fit again, the 21-year-old secured his first Tour-level match win for 21 months at Den Bosch last week, but even so, he surely would not have expected to clinch the best win of his promising career just days later.
"You don't want to know about the extensive list of injures I've had. That was 22 months out of the game," he said. "I can't wait to play in the next round." Kokkinakis faces Nicolas Mahut or Daniil Medvedev in the last 16.
Raonic recently hired former Grand Slam doubles champion Mark Knowles as his coach and remains confident of another good showing at the All England club,
"I was just a little too passive. I was letting him dictate too much," he said. "Obviously the disappointment is high right now, but whatever the result was this week, I don't think that's really going to change my chances at Wimbledon."