Andy Murray was bundled out in the second round of the ATP Challenger event in Rennes, France on Wednesday.
The former world No 1 lost 2-6, 6-4, 1-6 to unheralded Russian Roman Safiullin.
Murray is currently down at No 116 in the world rankings and has struggled on the tour in recent years after getting a metal hip.
Murray, who beat German Yannick Maden 6-3, 6-1 in the first round, is the first Grand Slam champion to compete in this Challenger Tour event, which started in 2006 when it was won by Frenchman Jo-Wilfried Tsonga.
The Challenger circuit is the second tier of men’s professional tennis, just below the ATP Tour.
Murray lost in the US Open first round in five sets to Greek Stefanos Tsitsipas. The match was, however, shrouded in controversy with Murray taking exception to Tsitsipas taking two lengthy bathroom breaks before winning 2-6, 7-6 (9/7), 3-6, 6-3, 6-4.
Picture: Andy Murray – ATP Challenger Tour/Twitter