Novak Djokovic tumbled out of the Indian Wells ATP tournament on Wednesday, upset 7-5, 6-3 by big-serving Croat Ivan Ljubicic in the fourth round.
While holder Rafa Nadal took three sets to overcame towering American John Isner 7-5, 3-6, 6-3, second seed Djokovic was eliminated in a match lasting one hour and 44 minutes.
The Serbian world number two, champion here in 2008, lost his serve in the sixth game of the second set and sent a forehand service return long to hand Ljubicic victory.
Ljubicic, the 20th seed, fired down 13 aces to record only his second win against Djokovic in seven meetings.
"I had a lot of opportunities and I didn't use many of them," Djokovic told reporters after converting only two of five break point chances.
"My execution was very bad and he played well when he needed to, he served well when he needed to.
"I was aware of his qualities before the match, and I was aware that if he serves well, then he can play relaxed on the return games. So that was the case," he added.
Although the 6ft 4in (1.93m) Ljubicic lost serve in the third game of the match, he broke back in the eighth and 12th to take the opening set in just under an hour.
Repeatedly unleashing first serves above 130 mph, he swept through the second set to book a place in the quarter-finals against 21st seed Juan Monaco of Argentina, who beat Spaniard Guillermo Garcia-Lopez 3-6, 6-2, 6-1 earlier in the day.
"I served well," said Ljubicic, who climbed to a career-high third in the world rankings in 2006. "My serve helped me, especially in difficult moments.
"You can't beat Novak only with a serve, but it does help you a lot if you can get a lot of free points off that shot. I was striking the ball nicely, and I felt like I could control the points off the baseline," he added.
Djokovic's early departure followed the premature exit on Tuesday of world number one and three-times champion Roger Federer, who suffered a shock defeat to Cypriot Marcos Baghdatis.
Twice champion Nadal, who beat Britain's Andy Murray in last year's final, broke the six-foot-nine Isner in the fourth game of the final set before sealing victory with a forehand winner down the line.
The Spaniard leaned backwards in delight to celebrate his advance to the last eight where he will meet Czech Tomas Berdych, who crushed Serbia's Viktor Troicki 6-1 6-3.
"John is a very difficult player to play against and I know I have to play a very good match if I want chances to win," left-hander Nadal said in a courtside interview.
"I try to play aggressive with the forehand and I am very happy with my performance," he added.
Sixth seed Swede Robin Soderling brushed aside Frenchman Jo-Wilfried Tsonga 6-3, 6-4 and will next take on either Murray or Nicolas Almagro. Murray, the fourth seed, and Spaniard Almagro are playing later on Wednesday.