Andres Romero made two late bogeys Thursday to drop into a tie for the Puerto Rico Open lead with Cameron Percy at 7-under 65.
Romero, the Argentine player who won the PGA Tour's 2008 New Orleans event and the European Tour's 2007 Deutsche Bank tournament, had an eagle and seven birdies on his first 15 holes to reach 9 under, then fell back with the bogeys on the par-4 seventh and par-5 eighth.
Percy, from Australia, had nine birdies and two bogeys on the Trump International course.
Blayne Barber and Jon Curran were a stroke back, and two-time major champion Angel Cabrera opened with a 67 to match Bill Lunde, Steve LeBrun, Brad Fritsch, Justin Bolli, Morgan Hoffmann, Brian Stuard, Peter Uihlein and Rafael Campos. Patrick Cantlay, the 20-year-old former UCLA player coming off a Web.com Tour victory last week in Colombia, shot 70.