Defending champion Andy Murray, the world tennis number three, has crashed out of the Miami Masters tournament, losing his opener 6-4 6-4 to America's world 101 Mardy Fish.
The Briton's defeat was the second shock in two days after world number two and last year's runner-up Novak Djokovic was bundled out in three sets by Belgian Olivier Rochus.
There were no such problems, however, for Swedish fifth seed Robin Soderling, the French Open runner-up, who progressed to the third round with a 7-6 (7-5), 6-0 win over Australian Peter Luczak.
Spain's 10th seed Fernando Verdasco saw off Israel's Dudi Sela 6-1 6-2 while 13th-seeded Russian Mikhail Youzhny eased past Santiago Giraldo of Colombia 6-0 6-1.
Three-time champion Venus Williams improved her own record at the Miami event while increasing the misery for beaten opponent Roberta Vinci with a 6-1 6-4 victory.
The American, who lifted the title at Crandon Park in 1998, 1999 and 2001, claimed her 12th consecutive match win after back-to-back titles in Dubai and Acapulco this season.
But life was dismal for Italian Vinci, the world number 55, who lost for the 12th time in a row to a top five player.
The third seeded Williams fired six aces in her 70-minute win, but also produced seven double-faults and saved six of the seven break points she faced.