Andy Murray was hardly at his best but did enough to book a semi-final spot at the Western & Southern Open in Cincinnati with a 6-3 6-3 win over Gilles Simon.
In baking conditions, the world number four rarely looked like worsening his six-one record against Simon, but struggled with his serve and his ground strokes at times before finding some consistency in the second set.
Murray had to encounter a handful of shaky moments in a match that was played at a slow, often mundane pace, but a gradual improvement in his first-serve percentages - he won 78% of the points on it - saw him home in an hour and 35 minutes.
He will now meet the winner of Rafael Nadal and Mardy Fish in tomorrow's semi-final.
After a delayed start because of a fire alarm, Murray appeared to have laid down an early marker when he broke serve in the opening game, eventually taking a fourth break point, only for Simon to instantly break back, showing his mettle to take a 37-shot rally.
The see-saw nature of the early exchanges looked like continuing into the third game as Murray earned himself two more break points, only to twice net before hitting wide and long to give Simon the game.
Murray steadied his ship with a hold in the fourth game and broke again in the fifth, coming in to punch home a forehand winner after a pedestrian rally that was no doubt as a result of the searing heat on court.
A less-than convincing hold then allowed the Scot to put daylight between himself and Simon at 4-2, but winning only 14% of points on his second serve meant he was having to fight, and he did so again as he went 5-3 up.
He found some much-needed rhythm in the ninth game, though, and, after earning himself three set points on Simon's serve, took the first set.
Murray was much more confident at the start of the second set and served out the first game without any bother, but two slack forehands at crucial stages of the next game allowed Simon to level at 1-1.
A lethargic start to the third game saw Murray in danger of losing his serve again, especially when Simon passed him after a poor drop shot to earn a break point, but Murray quickly got a grip of things and held out and then broke Simon to go 3-1 up.
A routine service game took him to within two games of the last four, and, after a hold apiece, he duly booked his place with well-timed drop shot.
Murray admitted afterwards that he had shown some early caution in order to get a foothold in the game.
"I have to play my game against him and it works very well," he told Sky Sports 1.
"I've seen many players try to blast him off. You have to wait for the right moments.
"I need to keep improving a few percent every day."