(Reuters) - Nick Kyrgios overcame a bout of nausea, a stiff back and saved three match points on the way to stunning top seed Rafa Nadal 3-6 7-6(2) 7-6(6) in the second round of the Acapulco International in Mexico on Wednesday.
The Australian fell to the floor in celebration after clinching the victory, before sticking a finger behind his ear and asking the raucous crowd to cheer louder.
Spaniard Nadal, who has won the tournament twice, took only one of his 10 break point chances and failed to put the match away despite leading 6-3 in the final set tiebreak before Kyrgios reeled off five straight points.
World number 72 Kyrgios improved his career record against Nadal to 3-3.
After dropping the first set, Kyrgios called for the trainer and said that he felt sick but would play on as he feared the media would "blow it up".
He returned to the court for the second set and immediately looked a different player.
At one stage a frustrated Nadal called for the crowd to quieten down, a request that received backing from Kyrgios, who screamed "shut up" together with an expletive, an outburst that brought him a warning from the umpire.
After calling for the trainer again between the second and third sets due to a sore back, Kyrgios then saved five break points in the sixth game of the final set.
He got out of jail again in the deciding tiebreak, particularly on the second match point when his volley caught the tape but toppled over and landed on the line.
Next up for Kyrgios is Swiss Stan Wawrinka, who defeated American Steve Johnson 7-6(5) 6-4.
Also on Wednesday, Mackenzie McDonald continued his recent strong form with a 6-7(7) 7-5 6-3 upset of fellow American Frances Tiafoe.
McDonald last week made it to the semi-finals of the Delray Beach Open, where he lost to eventual champion Radu Albot.
Third seed Isner posted the 400th win of his career, 6-4 6-4 over fellow American Sam Querrey.
(Reporting by Andrew Both in Cary, North Carolina; Editing by Peter Rutherford)