Nick Kyrgios served underarm once again but the fiery Australian fell away dramatically in the second set in a limp first-round exit at the Zhuhai Championships on Wednesday.
The 24-year-old Australian, who has been accused of tanking matches in the past, led the veteran Italian Andreas Seppi 4-1 in the first set, only to go down 7-6 (7/5), 6-1.
Kyrgios, who has had numerous run-ins with tennis authorities down the years, elicited a few giggles from a sparse crowd in southern China with an underarm serve in the first set.
Coasting 3-1 and 40-0 up, the 27th-ranked Kyrgios served weakly into the net, before surging into a 4-1 lead.
But the Australian, who then appeared to be troubled by his right shoulder, faded alarmingly from there and his previously dominant serve collapsed. He repeatedly felt his shoulder and his game disintegrated as he went down in the first-set tie break.
The second set was a non-contest as Seppi, 35, ranked 74th in the world, strolled into round two in 65 unpredictable minutes.
Kyrgios has divided tennis by serving underarm in the past, although it is within the rules, albeit rare to see from professionals.
The Australian firebrand says he deploys it for tactical reasons, but Spanish legend Rafael Nadal accused him of “lacking respect” by doing it.