Justin Thomas gave himself the ultimate lift ahead of the defence of his PGA Championship title after he cruised to a four-shot victory at the WGC-Bridgestone Invitational.
Thomas led by three overnight and produced a composed final-round 69 at Firestone Country Club to land his first World Golf Championship crown as the challenges of playing partner Rory McIlroy and Ian Poulter faded on the final day.
Dustin Johnson threatened to pile the pressure on the leader when he raced to seven under for the day after 10 holes and got to within three of Thomas, but the world No 1 could not keep his run going and he settled for a 64 and a share of third with Thorbjorn Olesen, who also closed with a six-under round to boost his Ryder Cup hopes.
Kyle Stanley won the race for second after a 68 lifted him to 11 under, but Thomas was relatively untroubled down the stretch and was content to grind out the pars with none of his rivals able to maintain a significant challenge.
McIlroy remained the most likely threat early on when he matched Thomas’ birdie at the second, and Thomas then opened the door for the chasing pack when a poor drive led to a bogey at the sixth.
But McIlroy had already dropped a shot at the short fifth and effectively took himself out of contention with a torrid run of three consecutive bogeys around the turn, while Poulter’s chances were scuppered when he dropped three shots in four holes in an outward 37.
Thomas gave himself breathing room when he converted from 10 feet at the 13th as Stanley slipped five shots behind when he followed birdies at 10 and 12 with back-to-back bogeys.
And, armed with a comfortable four-stroke lead with five to play, Thomas ensured he stayed out of trouble and eased home with five rock-solid pars to win on 15 under – making him the final champion at Firestone as the event moves to Memphis next year.
Stanley’s birdie at 16 proved lucrative as he pipped Johnson and Olesen to outright second, while US Open champion Brooks Koepka fired a 67 to complete the top five, finishing six strokes adrift of Thomas.
McIlroy’s all-round game became ragged from the moment he bunkered his tee shot to the short fifth and failed to get up-and-down, and three wayward drives at eight, nine and 10 cost him three shots and saw him tumble to eight under.
The 2014 champion was in danger of missing out on a top-10 finish when he found more sand at the 15th and carded his fifth bogey of the round, although he did raise a smile when he launched a 420-yard drive down the 16th and completed a good pitch and putt for a consolation birdie.
McIlroy’s frustrating 73 left him in a tie for sixth, while Poulter signed off with a 74 to close on seven under alongside Jason Day, who got to within two of the lead until suffering a huge collapse on the inward half.
World Golf Championships
August 6, 2018, 8:00pm
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The Australian raced into the reckoning with three straight birdies from the 10th, but he bogeyed the next two and then dumped a wedge into the lake guarding the front of the 16th green as he ran up a double-bogey seven.
Day dropped a further stroke at 17 to return a 73, while Tommy Fleetwood cost himself a large chunk of prize-money when he took six at the last to slip to six under after a 71.