Vijay Singh [Images] gave himself an ideal warmup for next week's PGA Championship, overcoming an erratic display with his putter to win the WGC-Bridgestone Invitational by one shot at Firestone Country Club on Sunday.

The smooth-swinging Fijian squandered an early two-stroke lead with an untidy run around the turn before holding on to clinch his first victory in a World Golf Championship event.

Joint pacesetter overnight with American Phil Mickelson and Britain's Lee Westwood, Singh fired a two-under-par 68 for a 10-under total of 270.

Westwood closed with a 69 to share second place with Australian Stuart Appleby (68) while Mickelson bogeyed three of the last four holes for a 70 and a tie for fourth at eight under with South African Retief Goosen (67).

Singh, who switched back to a belly putter last month, was relieved to sink a four-footer to par the last and end a PGA Tour title drought of 17 months.

"I didn't want to have a four-footer," the 45-year-old reporters after clinching his 32nd victory on the PGA Tour but his first this season. "I was kind of sweating on it.

"I just had to be comfortable over it. I hit on the right edge and it actually started right where I aimed and went in the hole. I'm really relieved.

"I had a good finish there at the end. I kept hitting a lot of good shots but my putting was not the best all day," added the Fijian who totalled 30 putts in the final round.

"Toward the end, it got kind of shaky."

Singh appeared to have the title firmly in his grasp when he birdied four of the first six holes in ideal conditions to forge two shots clear before his belly putter began to betray him.

LEAD SURRENDERED

One ahead at the turn, the Fijian briefly surrendered the lead to Mickelson when he missed a six-foot par putt at the 11th.

Although Singh recovered at the par-three 12th where he struck his tee shot to a couple of feet, he missed another six-footer to bogey the 13th.

After Mickelson collected his first bogey of the round at the 15th, where he was bunkered off the tee, the duo dropped back into a share of the lead with Westwood at 10 under.

Westwood faltered with a bogey at the 14th and Singh wasted a chance to regain the outright lead when he missed a five-foot birdie putt at the 16th.

Mickelson then dropped another shot at the 17th after missing the fairway off the tee to join Westwood at nine under, a stroke behind the pacesetting Singh.

After Mickelson collected his third bogey at the last, where he pulled his tee shot left of the fairway and struck his second into a greenside bunker, Westwood missed a 16-foot birdie chance on the 18th green to force a playoff.

His playing partner Singh had reached the green in regulation and two-putted from 30 feet for par to seal his first victory since last year's Arnold Palmer Invitational.

"This gives me a lot of confidence," Singh smiled. "I struck the ball really well, especially with my irons. Except for the second day, my driver was really good all week.

"This (win) puts me in a really good frame of mind going into next week and the rest of the season," he added, referring to the Aug. 7-10 PGA Championship at Oakland Hills.