Defending champion Andy Murray has been eliminated by local favourite Fabio Fognini 6-2 6-4 before a raucous crowd in his opening match at the Italian Open.
World No.29 Fognini frustrated the top-ranked Murray with drop shots and aggressive play.
The unpredictable Fognini led 5-1 in the second set and nearly let Murray force a third set with a series of errors but finally closed it out when he served for the match for a second time.
After completing the best year of his career last season, Murray has won just one of his eight tournaments this year.
Fans at the Foro Italico chanted for Fognini as if they were at a soccer match.
Earlier, four-time champion Novak Djokovic overcame a challenging first set to beat British qualifier Aljaz Bedene 7-6 (7-2) 6-2 in his opening match.
Bedene, who was born in Slovenia and obtained British citizenship two years ago, frustrated Djokovic for long stretches with his footspeed, keeping the ball in play and whipping surprising winners.
Also, David Goffin rallied past Fernando Verdasco 3-6 6-3 6-2, Tomas Berdych notched his 600th career win by beating qualifier Carlos Berlocq 6-3 6-4.
Jack Sock defeated Diego Schwartzman 6-4 1-6 7-5 and Alexander Zverev outlasted Kevin Anderson 6-4 4-6 6-4.