NEW JERSEY (AFP) - Bubba Watson fired seven birdies in a five-under par 65 on Thursday, outshining playing partners Jordan Spieth and Jason Day to seize a share of the first-round lead at The Barclays.
Two-time Masters champion Watson was atop the leaderboard alongside Colombia's Camilo Villegas and fellow Americans Spencer Levin and Tony Finau in the first of four events in the US PGA Tour's season-ending FedEx Cup playoffs.
On a tightly bunched board, the leaders held a one-stroke lead over New Zealand's Danny Lee, England's Paul Casey, Scotland's Russell Knox and Americans Jason Dufner, Cameron Tringale and Bryce Molder.
Another seven players were tied on 67, with newly crowned PGA Champion Day heading a group on 68 despite battling a bad back.
Spieth, the reigning Masters and US Open champion playing his first tournament since supplanting Rory McIlroy atop the world rankings, endured a tough day in a marquee group with Day and Watson.
The 22-year-old Texan carded a four-over par 74, just the third time in his last 33 rounds that he failed to break par.
"It was a very off-day," said Spieth, who posted his worst score of the year in relation to par.
"A little bit of rust with wedges combined with some poor decision making - and it just came out of nowhere," said Spieth, who called the round his worst "in years".
"Normally when I'm running that good, it doesn't turn like that," he said of the sudden struggles with his game.
"Typically when I hit the fairways I'm not over par," added Spieth, who hit 11 of 14 fairways. "That's what was weird about the round."
After teeing off at 10, Spieth had two birdies to make the turn two-under, but he had five bogeys and a double bogey against one birdie coming in.
"He just looked a little flat," said Australia's Day, who held off Spieth in the final round at Whistling Straits this month to win the PGA Championship, nabbing his first major title and rising to a career-high third in the world.
"It's understandable with all the stuff that he's been doing." Day, who skipped Wednesday's pro-am after aggravating a long-standing back injury on Tuesday, kept himself in the hunt despite some discomfort.
"There were a couple of swings out there that hurt," said Day, who nevertheless had three birdies and one bogey in his two-under effort.
Watson, meanwhile, had no complaints. His seven birdies included five in his first nine holes - the back nine of Plainfield Country Club.
"All in all it's a good round," said Watson, who regretted his two bogeys - after a poor shot at the par-three sixth and a three-putt at the ninth.
"If I just make a better swing on the par-three and then a two-putt, it's not too bad," Watson said. "I missed the cut the last time I played here, so we are ahead of the curve right now."