The world No4 looked to be coasting to a straightforward second-round win over Jeremy Chardry at the Cincinnati Masters when he took the first set and broke early in the second.
But Chardry hit straight back to level and trigger a bizarre sequence of games, in which the Scot broke twice more only for his French opponent to respond at the earliest opportunity on both occasions.
Chardry, the world No58, won the eventual tie-break before Murray corrected his wayward serve and quickly took command of the final set, breaking in the fourth game and ultimately wrapping up the match with little of the previous fuss, 6-3, 6-7 (3-7), 6-2.
“In the end it was frustrating,” said Murray, who beat Rafael Nadal and Roger Federer in winning the Toronto Masters last week and faces Latvian Ernests Gulbis next.
“I wasn’t making many mistakes in the first and he was making errors. In the second, I didn’t serve very well but my mistakes were more to do with the way I was hitting from back in court – too short. I stepped it up in third set.”
Earlier, world No1 Nadal progressed with a straight-sets win over American Taylor Dent, while second seed Novak Djokovic coasted past Serbian Victor Troicki.