Romero and Percy set the pace

Argentinian Andres Romero and Australian Cameron Percy shot to the top of the Puerto Rico Open leaderboard after superb opening rounds.

The pair were joint leaders at the end of day one, each signing for seven-under rounds of 65.

Romero started his day on the back nine, where he collected four birdies and added an eagle three at the second.

Three more birdies followed but he gave back strokes on two of his last three holes to sign for 65.

Percy had a similar story, birdying his first two holes and adding seven more to balance against two bogeys at four and 10.

Blayne Barber and John Curran led the American charge, sitting one shot back on six under.

Curran, starting on the 10th hole, dropped a shot in making four at the short 11th but found his form thereafter and made seven birdies along the way.

A group of nine closed in a share of fifth, two shots off the lead on five under.

Romero's compatriot Angel Cabrera was among them, doing the bulk of his work after the turn.

Cabrera's son, Angel Jr, had a forgettable day, lying second last following a round of 78.

Puerto Rican number one Rafael Campos was also in the group. He was just one under through 12 holes but hit five birdies in six holes - blemished by a bogey-four in the middle - to earn his place among the challengers.

Swede Robert Karlsson was the highest European challenger in a lengthy chasing pack on four under.