Fraser shot 4-under 68 to go 11-under for the tournament, one stroke ahead of a trio in second place heading into Sunday's final round.
Fraser, who shot a 66 Thursday and a 71 Friday, carded a steady bogey-free round at Golf Club Torino, which he said favored the methodical short game he honed as a kid in Australia.
"I grew up on a very tight, tree-lined golf course with tiny little greens and the emphasis was on getting it in play and hitting little shots around the greens," he said. "And that's exactly what this demands."
Friday's co-leader, Francesco Molinari, scored 71 Saturday and slipped into a three-way tie for second place with Nicolas Colsaerts, who shot 67 Saturday, and Joakim Lagergren, who turned in a sharp 67 that included five birdies and a bogey on the back nine.
Colsaerts drew even with Fraser on the 14th hole but fell a shot back with a bogey on the final hole.