Andres Romero and Cameron Percy posted matching rounds of 7-under 65 on Thursday and they share the lead after the opening round of the Puerto Rico Open.
Romero has one PGA Tour title to his credit, while Percy is searching for his first tour victory.
Blayne Barber carded a 6-under 66 and shares third place with Jon Curran on the Composite Course at Trump International Golf Club.
Two-time major champion Angel Cabrera is one stroke back at minus-5. He stands alongside Bill Lunde, Steve LeBrun, Brad Fritsch, Justin Bolli, Morgan Hoffmann, Brian Stuard, Peter Uihlein and Rafael Campos.
K.J. Choi, the highest ranked player in the field at world No. 65, opened with an even-par 72 and is tied for 80th place.
Romero, the 2008 Zurich Classic of New Orleans winner, played the back nine first on Thursday and got going with back-to-back birdies at 12 and 13. He converted a birdie effort at the par-3 15th and made the turn at minus-4 after making birdie at the par-5 18th.
The Argentine jumped to 6-under after he eagled the par-5 second. Romero followed with three birdies in the next four holes to get to 9-under.
However, Romero stumbled to a bogey at the seventh. He also bogeyed No. 8 to slip back to minus-7. Romero parred the last to end there.
Percy opened with birdies on the first and second. He faltered to a bogey on the fourth.
The Australian bounced back with three birdies in the next four holes to climb to minus-4.
Around the turn, Percy stumbled to another bogey on No. 10. He righted the ship with birdies at 12 and 13. Percy birdied the 16th and 18th to join Romero atop the leaderboard.
"Well, they were all pretty short except for on 12. I holed about a 25-footer on 12, just a little left-to-righter. That was a nice one. The rest of them were all five and six feet sort of thing," Percy said of his birdie putts. "Just drove the ball really nicely. I've been trying to not hit the ball too hard, so I just tried and hit three-quarters drivers and just kept the ball in play and I did that today and it was quite nice."
NOTES: Defending champion George McNeill mixed three birdies and two bogeys in a round of 1-under 71, which left him tied for 64th ... Scott Gardiner had a hole-in-one at the par-3 11th ... 17-year-old Si Woo Kim, who got his tour card via Q School last fall, withdrew after his round due to a back injury.