Manassero had six consecutive birdies to open his first round Thursday, and made four birdies in a row Friday in getting to 13-under 131 after 36 holes.
Mikko Ilonen and Peter Whiteford each had a 63 in the second round, with Ilonen moving into second at 11-under and Whiteford right behind at 10-under 134.
Ilonen's round was bogey-free and included six birdies over his last eight holes. Whiteford, who had two double bogeys Thursday, was 7-under over Nos. 12-18 Friday. That string included an eagle at the 622-yard, par-5 15th.
Joost Luiten, with a second-round 67, is alone in fourth at 9-under. Pablo Larrazabal, who was tied with Manassero after Thursday's play, was 2-under Friday and dropped into a tie for fifth at 8-under.
Manassero had a bogey at the fourth hole Friday and was 2-under through 10 before reeling off four consecutive birdies. A birdie at No. 17, a hole he bogeyed Thursday, got him to 13-under.