Nicolas Colsaerts set the early pace as the 72° OPEN D'ITALIA presented by DAMIANI got under way at Golf Club Milano on Thursday morning.
The big-hitting Belgian made a steady start to his round from the tenth, parring his first four holes before five consecutive birdies from the 14th to the 18th saw him turn in 31 and catapulted him to the top of the leaderboard.
Home favourite Francesco Molinari was in the feature group of the morning alongside Danny Willett and Miguel Angel Jimenez and he made the turn a shot behind the leader after also starting on the tenth.
The 2006 champion picked up shots on the 12th, 14th, 16th and 17th to sit four under after nine holes alongside Paraguay's Fabrizio Zanotti.
The 32 year old made birdies on the 11th and 14th and then rolled in an eagle on the par five 16th to sit four under through ten holes.
Jimenez registered an early bogey but a run of birdies from the 13th to the 16th moved him into a large group at three under which also contained 2009 US PGA Championship winner YE Yang and home competitors Joon Kim and Andrea Pavan.
Stewart Cink, the 2009 Open Championship winner, was in the group at two under alongside European Ryder Cup Captain Darren Clarke who had picked up an eagle on the 14th.
Tommy Fleetwood also eagled the 14th and sat in a large group at one under with Willett among those keeping him company.
Defending champion Hennie Otto, European Tour debutant Gavin Moynihan and two-time Major Championship winner Martin Kaymer were among the afternoon starters.
