Australian bad boy Nick Kyrgios shocked Novak Djokovic in straight sets at the Mexico Open, dealing a major blow to the world number two's hopes of regaining his mantle of invincibility.
The 21-year-old Kyrgios overpowered Djokovic with 25 aces in the 7-6 (11/9), 7-5 triumph as the Serb sought to rebuild confidence after his shattering second round defeat at the Australian Open in January.
The Australian, letting his tennis skills take centre stage instead of his tantrums, won 81 percent of his first-serve points as he dominated his first ever match with Djokovic.
"It’s what I dreamed of as a little kid, playing on these great venues against some of the greatest players in the world," said Kyrgios. "I never have a problem getting up for these matches.
"I wasn’t thinking about winning at any stage," he added. "I knew I had to stay in the moment because I've been in situations where matches have gotten away from me, so I had to stay switched on the whole time. I knew that if I just waited and waited, eventually I'd get my chance."
Djokovic fell in the Australian Open to Uzbekistan's Denis Istomin, then did not play again until this week.
After beating Slovakia's Martin Klizan he rallied to defeat Juan Martin del Potro, before losing his quarter-final to Kyrgios.
The world No. 17 Kyrgios delivered another giant killer performance as he also beat Rafael Nadal and Roger Federer in their first ATP tour level meetings.
He is the youngest player to record victories over the tennis Big Five -- Djokovic, Federer, Nadal, Andy Murray and Stan Wawrinka -- and is now 11-17 against top ten players.
Kyrgios will be seeking to reach his first final of the season when he faces big-serving American Sam Querrey in the semis.
Nadal bounced back from a break down in both sets to defeat Japan's Yoshihito Nishioka 7-6 (7/2), 6-3 and book his semi-final spot.
The second-seeded Spaniard, a two-time winner in Acapulco, hammered five aces in the battle between the two lefthanders.
"He is so quick," Nadal said. "I felt I needed to choose the right shots to do the damage. I was trying to hit the winner too early sometimes and too late other times, so it was tough to get my rhythm."
World No. 6 Nadal also kept his Acapulco unbeaten streak alive, having won 13 straight matches, and moved to 26-0 in sets in the ATP Tour event.
- Nadal advances -
Nadal advanced to a semi-final meeting with Marin Cilic. Nadal has won three of four career meetings with the Croatian.
"I am excited about playing this match," Nadal said. "He is one of the best players in the world."
The 30-year-old Nadal clinched Thursday's victory in the ninth game of the second set with an overhead smash at the net after Nishioka's return landed well short.
Nadal easily won the opening set tiebreaker by taking the first five points and then two out of the next four. He closed out the first set with a blistering cross-court forehand that froze Nishioka in his tracks.
Nishioka was his own worst enemy at times as the 21-year-old qualifier had no aces, committed four double faults and won just 50 percent of his second-serve points.
In the eighth game of the first set, Nishioka was up 40-15 and, despite having three challenges on the board, he failed to review a Nadal forehand that was ruled in but appeared to have sailed wide.
Third-seeded Cilic reached the semi-finals without hitting a ball as American Steve Johnson withdrew.
Johnson pulled out of his scheduled quarter-final on the hard courts with a right ankle injury he said he sustained in his victory over Ernesto Escobedo on Wednesday.
Unseeded Querrey eliminated fourth-seeded Dominic Thiem of Austria 6-1, 7-5 in their quarter-final match.