Wildcard Somdev Devvarman has reached the second round of the Dubai Tennis Championships after opponent Juan Martin del Potro was forced to retire from their first-round meeting.
Del Potro reached the semi-finals of the competition in 2012 and 2013, but had to pull out at the end of the first set due to an injury.
A recent wrist problem appeared to be hampering Del Potro in the first set, but he raced into a 2-0 lead after securing an early break.
Devvarman broke straight back before taking the tie-break 7-3, but Del Potro retired before the start of the second set.
The two met in this competition last year, with Del Potro victorious in straight sets.
