Mexico's Carlos Ortiz fired a five-under-par 67 to take the first-round lead of the LIV Golf Invitational Portland on Thursday, as the circuit's first event in the United States got underway.
Ortiz tallied seven birdies and two bogeys at Pumpkin Ridge Golf Club to establish a one-stroke lead over Dustin Johnson, who finished at four-under 68.
Pat Perez, Japan's Hideto Tanihara and South Africa's Branden Grace are tied for third at three-under, and Brooks Koepka, South Africa's Hennie du Plessis and Australia's Wade Ormsby share sixth place at two-under.
Among other notables, Bryson DeChambeau is tied for 14th at even par while Phil Mickelson and Spain's Sergio Garcia are tied for 30th at three-over.
The tournament is the second on the Saudi-backed circuit and the LIV debut for Ortiz, Perez, Koepka, DeChambeau and others. South Africa's Charl Schwartzel captured the LIV opener in mid-June near London. He is tied for 25th in Oregon at two-over par.
LIV events feature 48 players, last just three rounds and have no cuts. There also is a team aspect, with players grouped in four-man teams. The leading squad after the opening round is 4 Aces GC, featuring Johnson, Perez, Patrick Reed and Talor Gooch, who are at seven-under.
Stinger GC, an all-South African group consisting of Grace, du Plessis, Louis Ooshuizen and Schwartzel, are in second at five-under.