Nick Kyrgios denied suggestions he stopped trying during his four-set loss to Richard Gasquet at Wimbledon on Monday.
The Australian suffered a 7-5 6-1 6-7 (7-9) 7-6 (8-6) loss after an erratic performance at the All England Club.
Included was a carefree game early in the second set, appearing to deliberately give up points with Gasquet serving at 2-0 up.
Asked afterwards if he had tanked that game, Kyrgios hit back.
"Do you want to try and return Richard Gasquet's serve?" the 20-year-old asked a reporter.
"I'll give you the racquet and we'll see how many times you can return his serve also."
He added: "He served too good."
As for barely moving as he was aced during that game, Kyrgios said: "Of course I tried.
"He hits a serve past me as an ace, that's too good, that's too good. I did move. I did move."
The crowd booed Kyrgios during that game, but the talented world number 29 fought back before surrendering a 6-4 lead in the fourth-set tie-break.
"Just frustration. It's tough out there. I don't really know what else to say," Kyrgios said.
"I'm not perfect out there. I'm going to have ups and downs and it's the way you respond from that."