Feliciano Lopez of Spain plays a forehand during mens singles first round match against Stan Wawrinka of Switzerland on day two of the 2017 Aegon Championships at Queens Club on June 20, 2017 in London.
Lopez continued his hot run of form on grass having lost to Lucas Pouille in the Stuttgart Open final on Sunday as Wawrinka struggled to make the transition from clay to grass having lost to Rafael Nadal in the French Open final just over a week ago.
'What a way to win!' Lopez shocks second seed Wawrinka
The Swiss appeared to hurt his left knee during the first set and was given few free shots by 35-year-old Lopez, who produced some immaculate shots on his favourite surface in reaching the last 16 of the Wimbledon warm-up event.
After his defeat by Nadal in the Paris final, Wawrinka added Paul Annacone to his coaching team as a grass court specialist.
The American had previously coached Roger Federer and Pete Sampras, who between them have taken 14 Wimbledon titles.
Stan Wawrinka of Switzerland looks dejected during mens singles first round match against Feliciano Lopez of Spain on day two of the 2017 Aegon Championships.
Image credit: Eurosport
Swiss Wawrinka hopes Annacone will improve his prospects at Wimbledon, where he has never progressed beyond the quarter-finals.
He was below his best on Tuesday as Lopez produced some deft touches to support his big serve.
"I came here with a lot of confidence and tennis is a lot about confidence," Lopez told the BBC.
It was the second upset of the day before a blistering Centre Court at Queen's with Australian world number 698 Thanasi Kokkinakis stunning third seed Milos Raonic in straight sets.
Results from the Queen's Men's Singles Round 1 matches on Tuesday