Angel Cabrera and Jhonattan Vegas have taken a joint-lead at the top of the early Barbasol Championship standings following an opening-round 65.
The duo dominated the par-five holes to race ahead at Grand National's Lake Course, although a chasing pack of five contenders remain in touching distance heading into day two.
Cabrera, one of two Major champions competing in the tournament, eagled the par-five 13th and birdied the other two in a bogey-free round.
It was a similar story for Vegas, who matched his rival throughout to remain well on course for just a second tour title of his career in the steamy conditions.
Blayne Barber is among those a stroke back on five-under, along with Martin Laird, Shawn Stefani, Matt Bettencourt, Michael Kim, Lucas Lee and Ben Crane - the latter of whom is making his first appearance in this event.
Further down the day one leaderboard, Michael Johnson carded a round of 67 on his pro debut to remain in contention on home soil.
Daniel Lewis
