AKRON (AFP) - Australia's Adam Scott won the Bridgestone Invitational on Sunday, posting a final-round 65 to notch a four-stroke victory over Luke Donald and Rickie Fowler. Scott, with Tiger Woods' former caddie Steve Williams on his bag, finished with a four-round total of 17-under 263. The Australian won his first elite World Golf Championships title. World number one Donald and Fowler both shot 66 for 267 while Japanese teen phenom Ryo Ishikawa carded a 69 to finish with a share of fourth alongside Australian Jason Day (69) on 268. Ishikawa, playing in the last group, challenged for the lead but Scott pulled away with birdies at 12 and 14 as the 19-year-old Japanese star three-putted 15 to fall back. At the 12th, Scott chipped in and at 14 he rolled in a putt from nearly 30 feet. He played the last 26 holes without a bogey and his winning total was the lowest at Firestone since Woods' 259 in 2000. Ishikawa's bogey from the trees at the final hole cost him a share of second place. Scott said it was a bonus having a caddie of Williams' experience. Williams caddied for Woods in seven victories at the Firestone course. Woods sacked Williams this summer and the New Zealander, who had caddied for Scott during Woods' recent injury layoff, made his relationship with the Australian permanent. "Obviously he has such a great knowledge of this golf course and the greens," Scott said. "He's seen a guy play incredible golf, the best golf anyone has ever played around here, so many times.