World number four Andy Murray struggled into the US Open third round on Friday, clinching a 6-7 (5/7), 2-6, 6-2, 6-0, 6-4 victory over Dutchman Robin Haase, who needed regular treatment on a back injury.
Murray shook off his slow start to take a commanding fifth-set lead, then fended off a last furious charge from Haase to line up a meeting with 25th seed Feliciano Lopez for a place in the fourth round.
Murray beat the Spaniard in the quarter-finals at Wimbledon.
"I just wasn't playing well at the start of the match, I was moving really poorly and that's not good for my game. Once I started to move better towards the end of the third set, my game was so much better," said Murray.
Haase, whose career has been blighted by a succession of knee problems, cruised into a two set lead before he needed three separate visits from the trainer to tend to his injured back.
"I've been carrying it a while already. It is coming and going, because it's not from the leg it's actually from the hip, back, and yesterday nothing, it was fine, I played doubles, the whole day was good," said Haase.
"Today I woke up at two o'clock that I couldn't sleep for two hours, I was just walking down the corridor in the hotel because I was in so much pain.
"It's strange that it comes in the night when I just lie down but something just moves into a bad spot and I wake up and have the pain and it's tough for the physios to get it fixed."
Murray, who made the final here in 2008, won 13 games on the trot from 3-2 in the third set to 4-0 in the decider before Haase suddenly, and dramatically, launched a mini-recovery.
The 24-year-old Dutchman levelled at 4-4 before the Scotsman broke to lead 5-4.
Haase saved two match points, the second on a successful challenge to a forehand which was called out, before Murray clinched victory when his opponent went long.