Rory McIlroy closed with two bogeys to take the gloss off his opening round at the Deutsche Bank Championship in Boston.
The Holywood star carded a one-under 70 in his opening play-off event.
The world number one was in contention to be among the early leaders after moving to three under with back-to-back birdies on the third and fourth holes –having started on the 10th.
McIlroy hit a stunning shot at the 202-yard par-three third at TPC Boston before rolling in a birdie from five feet.
He posted another two after another brilliant iron into the 166-yard 16th which was followed by an eight-foot birdie putt to wipe out an earlier bogey on the 14th hole.
He then fired an eagle attempt past the cup on the par-five 18th, before making the return birdie putt from six feet to go under par for the day.
McIlroy followed his birdie on the third by driving the 298-yard par-four fourth, but his eagle attempt failed to drop as he finished out for a birdie.
But missed par putts from less than eight feet at both the eighth and ninth to slip back into the pack.
England’s Luke Donald and American Colt Knost both carded four-under 67s to take a share of the clubhouse lead, with US PGA champion Justin Day a further shot back having started his round with three straight birdies.
Jordan Spieth’s inconsistent form continued as he carded a four-over 75 following on from missing the cut at The Barclays.