(Reuters) - Australia's Alex de Minaur fought back from a set down to beat former world number one Andy Murray 4-6 6-2 6-4 in the last 16 of the Zhuhai Championships on Thursday.
Murray, who won his first ATP tour singles match in nine months in Tuesday's first round, battled for two hours and 42 minutes on court before his 20-year-old opponent prevailed.
Murray dropped serve early on before storming back with two breaks of his own to take the first set. However, he faded in the second and looked to be struggling physically in humid conditions.
De Minaur then wrapped up the deciding set to deny Murray a dream comeback on the tour and he will next face Borna Coric in the quarter-final.
"My feeling tonight was that at points I played very well, but I didn't feel like I was able to sustain my level," Murray told reporters.
"The second set I dropped and also in the third set, in comparison to the first set, it was a little bit scrappy. There was some good points in there, some good stuff, but for me physically I was struggling.
"In terms of the level that I was playing at it was good, but I just wasn't able to sustain it for long enough."
Meanwhile, top seed Stefanos Tsitsipas was forced to retire from his last-16 encounter with Adrian Mannarino before the deciding third set after he complained of shortness of breath.
"I'm very sorry to all the fans who came to see me play tonight in Zhuhai," said the Greek, who won the Laver Cup with Team Europe last weekend.
"I was trying my best but unfortunately I had to retire as I was struggling to breathe out on court."
(Reporting by Rohith Nair in Bengaluru; Editing by Christian Radnedge)
