KIAWAH ISLAND, South Carolina (Reuters) - Rory McIlroy tightened his grip on a second major title by sinking a 10-foot birdie putt at the par-four 12th to forge six strokes clear with six holes left in Sunday's final round of the PGA Championship.
The Northern Irishman's fourth birdie of the day on the challenging Ocean Course at Kiawah Island Gold Resort put him at 11 under overall as he cruised toward the finish line in the year's final major.
McIlroy, who clinched last year's U.S. Open at Congressional by a staggering eight shots, repelled a withering early charge by Ian Poulter with birdies at the second, third and seventh before moving ahead on the more difficult back nine.
Britain's Poulter, who made a sizzling start with birdies on the first five holes before adding another at the seventh, was tied for second at five under with Swede Carl Pettersson.
Clad entirely in white, the dapper Poulter had three holes to play while Pettersson had six.
Englishman Poulter briefly closed to within two strokes of the lead before his bid for a maiden major title unraveled with a run of three consecutive bogeys from the 13th on a steamy afternoon at Kiawah Island.
Pettersson, despite being slapped with a two-stroke penalty for grounding his club in a hazard on the first hole, responded well with three birdies in five holes from the third before coming unstuck after the turn.
Britain's Justin Rose held the clubhouse lead at four-under 284 after closing with an eight-birdie 66.
Also at four under were defending champion Keegan Bradley, after 16 holes, fellow American Bo Van Pelt, after 12, Swede Peter Hanson, after 13, and Australian Adam Scott, after 12.
Four-times champion Tiger Woods, hunting his first major crown in over four years, was a further stroke adrift after 14 holes, having largely struggled off the tee and also with his putting in the final round.
McIlroy, who moved three shots clear by firing a five-under-par 67 in the weather-delayed third round which was completed earlier on Sunday, is aiming to end a run of 16 majors won by different players.
Pettersson was handed a two-stroke penalty because his clubhead touched a dry leaf during his backswing inside a hazard line on the opening hole, transforming the par he recorded there into a double-bogey six.
The Swede was informed of the decision by PGA Tour rules official David Price after he teed off at the par-four fourth. Pettersson remarkably went on to birdie that hole, the fifth and the sixth.
(Reporting by Mark Lamport-Stokes; Editing by Frank Pingue)