Britain’s Andy Murray beat Mackenzie McDonald 3-6 6-4 7-5 in the Washington Open’s first round in his fourth match following hip surgery in January.
Murray, 31, converted his seventh match point after more than two-and-a-half hours on court against the American.
The ex-world number one was broken in two of his first three service games as he lost the first set before levelling and taking a 73-minute final set.
He will now play fellow Briton Kyle Edmund, 23, in the second round.
Edmund beat Murray at Eastbourne in the third match of his return during the grass court season before the Scotsman pulled out of Wimbledon as he felt it was “too soon” to play five-set matches following his rehabilitation.
Murray was made to fight hard against 23-year-old McDonald after losing the opening set in 40 minutes to the man ranked 80th in the world.
Murray, whose world ranking has dropped to 832, broke in the ninth game of the second set to take a 5-4 lead and served out to take the match to a decider.
He was then 5-4 up and serving for the match in the third set but McDonald saved five match points then converted his second break point to draw level at 5-5.
But Murray immediately broke back – in a game that included a controversial call when McDonald’s racket was adjudged to have crossed the plane of the net with the score 30-30 – before serving out to reach the second round.