London, June 20: Juan Martin del Potro withdrew from the Queen's Club Championships due to a knee injury suffered in his first-round win over Denis Shapovalov.
The 2009 US Open champion spent almost three months out of action with a knee problem before returning in May, but suffered more misfortune in London on Wednesday (June 19).
Del Potro slipped in the second set on another rain-affected day of the tournament and although he went on to win 7-5 6-4, the former world number three later pulled out of his first event of the grass-court season less than two weeks before Wimbledon starts.
The luckless Argentine was left with a swollen right knee and is taking no chances after missing so much time in an injury-plagued career.
Feliciano Lopez receives a walkover into the quarter-finals in the absence of Del Potro.
Lopez strongly denied "false accusations" made in reports of an alleged match-fixing scandal at Wimbledon two years ago after he beat Marton Fucsovics 6-7 (4-7) 6-3 6-4 in his opening match at Queen's - a day before he is due to play doubles with the returning Andy Murray.
Stefanos Tsitsipas was leading Kyle Edmund 6-3 3-3 when play was suspended due to the miserable weather and fading light.
Stan Wawrinka saw off Dan Evans 6-3 6-4, while Milos Raonic, Lucas Pouille, Jeremy Chardy and Aljaz Bedene also advanced a day after play was washed out.
The matches between Nick Kyrgios and Roberto Carballes Baena and Grigor Dimitrov and Felix Auger-Aliassime were postponed for the day.