Andy Murray was beaten 6-1 1-6 6-4 by Lucas Pouille in the first round of the Western & Southern Open in Cincinnati.
Murray, back on court after pulling out of the Citi Open in Washington earlier this month, had won all four previous meetings with the Frenchman but was below par and too inconsistent against the 16th seed.
The Scot, a two-time winner in Cincinnati, was competing in only his fourth tournament in 13 months following hip surgery in January.
“I only lost four more points in the match than him. It was tight,” Murray told the ATP’s official website.
“He’s a top-20 player. If I can improve by 10, 15 per cent, you turn a lot of those matches around.”
Former world number one Murray was broken in the first game as Pouille took the opening set in just over 30 minutes.
Murray hit straight back to level the match after winning the second set 6-1 in convincing style.
He broke Pouille in the first game and never looked back, stepping on to the front foot, finding his range and playing more aggressively.
Pouille was broken for a second time to trail 4-1 and after Murray comfortably held, the Frenchman lost his serve again in the seventh game to send the match into a decider.
But Murray lost his way again and could not contain the impressive shot-making of Pouille, who dominated the third set to win in an hour and 53 minutes.
Pouille pounced on Murray’s nervous start to the decider as the Briton double-faulted on the first point before being broken in the opening game.
Pouille moved comfortably into a 2-0 lead and although Murray held serve in the next, he failed to convert a break point in the fourth game and fell 3-1 behind.
Murray pulled it back to 5-4, having saved match point on his serve as he trailed 5-3, but Pouille held his nerve to hold serve in the 10th game, taking the set 6-4 and sealing a deserved victory.
Later, British number one Johanna Konta exited the tournament after being beaten 4-6 6-3 6-4 by Belarus’ Aryna Sabalenka.
Konta started strongly, taking the first break of the game at 3-3, but Sabalenka immediately broke back.
From there, the pair thrashed it out in a difficult game which saw Konta reach five break points, ultimately breaking her opponent with a powerful forehand to lead 5-4 and hold on to take the set.
After taking a 3-1 lead in the second, Konta’s momentum began to drop as she made five double faults and lost two service games, with the world number 34 taking advantage and holding Konta at love to take the set 6-3 and levelling the match.
Double faults continued to plague Konta’s game in the third set as she dropped serve at 3-3 and while Sabalenka struggled to convert three match points at 5-4, she did not waste the opportunity on her own serve, taking the set and the match 6-4.