Britain's Jack Draper suffered a narrow first-round defeat by Hubert Hurkacz at the Monte Carlo Masters.
World number 39 Draper lost 6-4 3-6 7-6 (7-2) to the Polish 10th seed in a close clay-court meeting.
Draper had broken Hurkacz as he served for the match at 5-4 in the third to stay in contention but could not make inroads in the tie-break.
Earlier, third seed Carlos Alcaraz withdrew from the tournament with a muscle injury in his right forearm.
The Wimbledon champion had been due to play Canada's Felix Auger-Aliassime on Wednesday and practiced in Monte Carlo with his forearm taped.