A brilliant birdie blitz on Sunday afternoon saw Australian Marcus Fraser take over at the top of the Italian Open leaderboard.
Fraser, who held a share of the lead at the halfway stage, hit the front on day four after firing seven birdies in his first 11 holes to move to 19 under par.
Englishmen Ross Fisher and Matt Wallace were a single shot back in a tie for second, with Thailand's Kiradech Aphibarnrat another stroke behind in fourth as the players took advantage of favourable scoring conditions.
Fraser began the day five shots behind overnight leader Wallace after Saturday's 72 saw him drop out of contention.
But he made amends on Sunday, opening his final round with back-to-back birdies before reeling off a hat-trick of gains from the fourth to get to 17 under.
Fraser then rolled in from 20 feet to pick up another shot at the eighth and grab a share of the lead.
And after sending his approach at the 11th to within six feet of the hole, the 39 year old knocked in his birdie putt to take the outright lead.
Fraser's playing partner Fisher made five birdies on the front nine before adding another at the tenth to get to 18 under.
Fisher, who set the course record at St Andrews this time last week, will be hoping for more Sunday fireworks this time around.
Wallace began his fourth round with a birdie to get to 18 under but he stayed there after making pars at his next five holes.