Andy Murray lost in the first round of the Winston-Salem Open as his return to singles continued following major surgery.
The 32-year-old lost 7-6 (8) 7-5 to American Tennys Sandgren in a rain-delayed match at North Carolina's Wake Forest University.
Murray underwent hip surgery seven months ago in a bid to save his career and returned to singles action last week, when he lost 6-4 6-4 to Richard Gasquet at the Western and Southern Open in Cincinnati.
Hundreds turned out to see him in North Carolina, with many sticking around after play was delayed for several hours due to rain.
There were some flashes of form from the Briton, who accepted a wildcard to the ATP 250 event, but world number 73 Sandgren proved too strong.
Murray struggled after losing the first set, being broken in the second set's opening game and falling 3-0 behind.
But he broke back twice to level the second set at 5-5, before netting a forehand in the 11th game and handing the American the victory.
Murray had initially returned in doubles competition but later confirmed he would not play in the format at the US Open as he focuses on his singles career.
