Paul Dunne fired a six-under 66 to sit in a three-way share of the lead after the opening round of the Corales Puntacana Resort and Club Championship.
Dunne mixed eight birdies with two bogeys at the Corales Golf Club in Punta Cana in the Dominican Republic on Thursday.
The Irishman is joined by Australian Matt Jones and American Joel Dahmen at the top of the leaderboard.
South Korean Im Sung-jae is outright fourth after a five-under 67, while a group of six including Aaron Baddeley are a shot further back.
Defending champion Brice Garnett could only manage a 71 to be back in a tie for 43rd.
Dallas Cowboys great Tony Romo, who missed the cut last year, struggled to a seven-over 79 that included a triple bogey at the par-four eighth.