Miami: Two-time defending champion Novak Djokovic crashed out in the fourth round of the Miami Masters while last year's runner-up Andy Murray eased through to the quarter-finals in straight sets. (Agencies)
World number one Djokovic was stunned 6-2, 6-4 by German 15th seed Tommy Haas but US Open winner Murray had no such difficulties, breezing past Italy's Andreas Seppi by the same score in the USD 8.5 million ATP and WTA hardcourt event.
"There are days when you don't feel good on the court and this is one of those days," Australian Open champion Djokovic said.
The Serb lost for just the second time this season, never getting to grips with Haas, who kept Djokovic off his game with a number of skillful shots.
"All the credit to him. He was the better player. As far I am concerned it is the worst match I have played in a long time," Djokovic said.
Haas, who turns 35 next week, advances to the last eight where he will face Frenchman Gilles Simon who outlasted Djokovic's countryman Janko Tipsarevic 5-7, 6-2, 6-2.
Haas easily won the first set then clinched victory on his second match point with a forehand winner to the open court, ending the 80 minute match.
Djokovic, who had won this event three times (2007, 2011, 2012), had one double fault and won just 54 percent of his second serves.
This is the first time since 1999 Haas has beaten a world No.1. He defeated Andre Agassi in three sets at the Grand Slam Cup for his only other win over a world No. 1 in 15 contests.
Miami: Two-time defending champion Novak Djokovic crashed out in the fourth round of the Miami Masters while last year's runner-up Andy Murray eased through to the quarter-finals in straight sets.