Robert Rock and Laurie Canter set the clubhouse target on a low-scoring opening day at the Italian Open but they had an intimidating chasing pack behind them at Gardagolf Country Club.
The stunning layout on the shores of Lake Garda last hosted the national Open in 2003 and was this week making its first appearance at a Rolex Series event, with the players competing for a prize fund of seven million US dollars.
Recent rain has softened the course up and the elite field took full advantage, with English duo Rock and Canter carding rounds of 63 to get to eight under and lead by two.
There was then a stellar group at six under, with 2016 Masters Tournament winner Danny Willett, Ryder Cup duo Ross Fisher and Thomas Pieters, and Hero Indian Open champion Matt Wallace all carding rounds of 65.
Home favourite Francesco Molinari - a two-time winner of this event - was going in search of back-to-back Rolex Series wins and he was at five under alongside English trio Matthew Fitzpatrick, Lee Slattery and Lee Westwood, South African Darren Fichardt and Frenchman Mike Lorenzo-Vera.
Rock won the first of his two European Tour titles at this event in 2011 and he recovered from a bogey on the second with birdies on the fourth and sixth, an eagle on the seventh and a hat-trick of gains from the ninth.
Canter also eagled the seventh after birdies on the first, fifth and sixth, and when he made another gain on the tenth, he too was six under.
The 28 year old birdied the 13th to hit the front on his own and Rock almost chipped on the 15th to get back into a share of the lead. An approach to tap-in range on the 16th nudged Rock ahead but Canter birdied the same hole and they were the men to catch.
Willett started on the tenth and birdied the 13th and 15th before a glorious approach to the 16th brought another gain. He maintained momentum with a birdie on the first, and a 20-foot putt on the third and excellent tee-shot on the eighth had him right in the mix.
Fellow Englishman Fisher birdied the 13th, 17th and 18th but a bogey on the sixth then threatened to throw him off course. Last season's runner-up is made of stern stuff, however, and he birdied the seventh and eighth before holing his approach from 104 yards on the ninth for a closing eagle.
Playing partner Pieters also needed a big finish after bogeys on the 17th and 18th took the gloss off a start that had seen him pick up shots on the tenth, 13th, 15th and 16th. The Belgian made further gains on the fourth, seventh, eighth and ninth in an excellent recovery.
Wallace has been a picture of consistency of late and the Englishman was bogey-free with birdies on the 13th, 14th, 16th, first, seventh and ninth.
Molinari extended his bogey-free run to 62 holed in a typical ball-striking masterclass while Slattery's card also contained five birdies and no bogeys, with Fitzpatrick making three birdies and an eagle.
Westwood had two bogeys on his card, while Fichardt and Lorenzo-Vera each recorded a single blemish.
