Andres Romero carded a six-under 66 to grab a one-shot lead after the first round of the Puerto Rico Open on Thursday.
The Argentinian, whose only PGA Tour win came in 2008, produced a bogey-free opening round that included six birdies in Rio Grande.
Austrian Sepp Straka is in outright second after firing a five-under 67, with a group of nine players a shot behind him.
Ben Crane, Ollie Schniederjans, David Hearn, Roberto Castro, Martin Piller, Roberto Diaz, Joey Garber, Nate Lashley and Alex Kang are all at four under.
Former champions D.A. Points and Scott Brown made decent starts, shooting one-under 71s.