Golf: Bradley grabs share of Valspar lead but Spieth struggles to 76 and risks missing cut

(REUTERS) - Former PGA Championship winner Keegan Bradley converted several crucial putts to grab a share of the first-round lead at golf's Valspar Championship on Thursday, while Jordan Spieth's title defence got off to a horrendous start.

Bradley, who had to transition to a non-anchored putter when a ban went into effect this year, mixed five birdies with one bogey for a four-under 67 that put him in a three-way tie with Charles Howell III and Ken Duke.

They led fellow American Chesson Hadley by one stroke, while Spieth fell nine strokes behind as he struggled on greens that he said were among the slowest he had ever encountered on the PGA Tour.

Bradley, 29, who missed four of his last five cuts on the Tour, had no trouble adjusting to the greens during a blustery round at Innisbrook Resort's Copperhead Course in Palm Harbour, Florida, where needed just 25 putts.

"I really had a good day on the greens, which was nice because it's been awhile," said the 2011 PGA Championship winner, who drained a crucial nine-foot putt for par on his penultimate hole, the par-three eighth, before closing with an up and down for par.

Spieth was returning to the scene of his play-off victory that kicked off one of the game's greatest seasons as he went on to triumph at the Masters, US Open, John Deere Classic and Tour Championship and FedExCup play-offs title.

But the world No. 1, who started his round on the par-four 10th, was unable to rediscover that form, as he bogeyed five of his first seven holes en route to a disappointing five-over 76 that left him in a tie for 117th.

The poor round leaves him fighting to make a cut for the second time in his last three starts after missing out at last month's Northern Trust Open.

"It was a very tough day," said Spieth, whose win at the Valspar last year was the first of five on the PGA Tour for the Texan. "I got off to a poor start and I was behind the eight-ball with gusty wind on a tough golf course."