Rafael Nadal suffered his first ever defeat at the Rome Masters on Wednesday, falling to unseeded countryman Juan Carlos Ferrero in the second round.
The three-time defending champion and second seed had won all 17 of his previous matches at the tournament but fell 7-5 6-1 to Ferrero.
Nadal twice called for the trainer during the contest after struggling with a foot injury.
The 21-year-old had not lost on clay since being beaten by world number one Roger Federer in the Hamburg final last May.
Nadal had won 22 successive matches and four titles on the surface since then, including his third consecutive French Open crown.
He came into this event on the back of consecutive titles at Monte Carlo and Barcelona.
Ferrero, who had won just one of seven previous encounters with Nadal, saved all five break points he faced during the match and was dominant in the second set as he reeled off five successive games to close out the match.
Although the 28-year-old won the championship in 2001, this victory may go down as his most memorable at the event, considering the circumstances.
Nadal, whose record is now 117-4 on clay since the start of 2005, had not lost to a fellow Spaniard on dirt since David Ferrer beat him at Stuttgart in 2004.
The world number 23, Ferrero will now face unseeded Stanislas Wawrinka, who was a 6-2 7-6 (7/5) winner over 16th seed Andy Murray.
Twelfth seed Fernando Gonzalez, the runner-up to Nadal last year, secured his place in the third round with a 6-3 6-2 victory over Evgeny Korolev.
The Chilean's next opponent is unseeded Spaniard Nicolas Almagro, who posted one of three other second-round upsets with his 6-4 7-5 win against seventh seed David Nalbandian.
Also making an unexpected exit was fifth seed David Ferrer, who fell victim to unseeded Czech Radek Stepanek 4-6 6-2 6-1.
The other surprise was turned in by Russia's Igor Andreev, who ousted 13th seed Juan Monaco 4-6 6-1 6-4.
There were no surprises for third seed Novak Djokovic of Serbia or fourth-seeded Russian Nikolay Davydenko, both of whom cruised into the third round with straight-sets victory.
Australian Open champion Djokovic was a 6-4 6-0 victor over Steve Darcis, while Davydenko proved too strong for Mario Ancic as he eased to a 6-2 6-2 victory.
Eighth-seeded American James Blake also took care of business in a 7-6 (7/5) 3-6 6-1 win over Italy's Andreas Seppi.
