(CNN) -- World number four Andy Murray crashed out of the Rome Masters to qualifier Juan Monaco on Wednesday.
Murray bows his head as he faces up to defeat by world number 58 Monaco.
Murray, who reached the semifinals in Monte Carlo, continued his poor run on the clay in Rome with a 6-1 3-6 7-5 defeat to the Argentine.
It was only his fourth defeat of the year which has seen him pressurize Novak Djokovic, the defending champion in Rome, for the world number three spot.
Monaco will now face Marin Cilic in the last 16 after the tall Croatian beat Christophe Rochus of Belgium 6-0 5-7 6-2.
Top two seeds Rafael Nadal and Roger Federer were untroubled as they reached the third round.
Nadal, unbeaten on clay this season, needed just one hour 19 minutes to beat home hope Andreas Seppi 6-2 6-3.
Second seed Federer beat Ivo Karlovic of Croatia 6-4 6-4 while Spain's Tommy Robredo beat Phillip Kohlschreiber of Germay 6-2 7-6 to earn a match at the same stage with Djokovic.
In a first round match held over because of poor weather in the Italian capital, Richard Gasquet upset compatriot and ninth seed Jo-Wilfried Tsonga 7-6 6-4.
Murray, on his least favorite surface, made a superb start at the Foro Italico as he took the opening set for the loss of only a game, Monaco making 16 unforced errors.
The second set saw several breaks of service but Monaco moved ahead decisively for 5-3 and held his own delivery to level.
The topsy-turvy nature of the match continued in the deciding set with Murray coming from 4-2 down to lead 5-4 before conceding the final three games of the match.
Monaco closed it out after two hours and 40 minutes on his third match point.