LONDON: Juan Martin del Potro progressed to round two at a rain-affected Queen's on Wednesday, but at a cost as the Argentine ended the match hobbling after slipping on a damp court.
Del Potro served out for a 7-5, 6-4 win over Denis Shapovalov despite hitting the deck in the eighth game of the second set.
The 2009 US Open champion is playing in only his fifth tournament of the season after fracturing his right kneecap last October.
Del Potro has pulled out of the doubles, but could still line up to face Feliciano Lopez in round two of the singles.
Lopez also had an eventful day as he was forced to strenuously deny reports in Spain that a match he and doubles partner Marc Lopez lost at Wimbledon in 2017 was fixed.
"I feel it is extremely important to come to you and absolutely deny any link with the events described in relation to the allegations of match fixing," said Lopez after coming from a set down to beat Marton Fucsovics 6-7 (4/7), 6-3, 6-4.
Lopez is due to partner Andy Murray on his return to court after hip surgery in the doubles.
Three-time Grand Slam champion Stan Wawrinka overcame a series of rain delays to beat Britain's Dan Evans 6-3, 6-4.
However, three first round matches are still to be completed after rain washed out much of a second consecutive day's play.
Top seed Stefanos Tsitsipas took the first set against Kyle Edmund before play was finally postponed.