Matt Kuchar has posted a six-under 65 to open a four-shot lead in the Mayakoba Golf Classic in Mexico.
Kuchar hit a wild drive to the right into mangroves on the par-4 14th and had to get up-and-down to salvage a bogey at El Camaleon Golf Club.
That was the only blight on American veteran's scorecard as he aims for his first PGA Tour title in more than four years.
Kuchar saved par from just off the green at the 18th to finish at 20-under 193, four shots ahead of Korean Whee Kim, who had a 66.
It matches the largest 54-hole lead of Kuchar's career. He also led by four at the Houston Open in 2014, when he wound up losing to Australian Matt Jones in a playoff.
Richy Werenski and New Zealander Danny Lee both carded rounds of 67 to be tied third and five shots back of Kuchar.
PGA Tour rookie of the year Aaron Wise (63) and Cameron Champ (69), who has already won this season at the Sanderson Farms Championship, were joined by J.J. Spaun (65) at 14 under and a share of fifth.
Ryder Cup captain Jim Furyk had a 66 and was in a group at 13-under.
Australian PGA Tour rookie Cameron Davis had a 72 on Saturday to be tied for 53rd at five under while his countryman Jones slide to 71st after a 74 left him one under.