The 32 year old won his second European Tour title in Korea last year, but then suffered a freak neck injury lifting his son Archie over his head.
At one stage there were questions as to whether he would play again, but Fraser showed his return to form and fitness with a round that included a run of four consecutive birdies from the fourth.
"It was great - I played really well all week," he said. "It was great to come out today and play well on a Sunday at Wentworth. It's obviously a big confident boost more than anything, everything went right today and apart from a couple of bogeys on the back nine, very happy."
With Luke Donald and Lee Westwood five under on the course Fraser admitted he was likely to fall short of the title, but a top-ten finish looked likely.
"I think the three bogeys hurt me on the back nine," he added. "I think four, possibly five, the two par fives to finish with, and 17 is down breeze, and 18 is not easy, but anything is possible. We'll wait and see, but I think maybe a couple shy.
"Thinking I would never play golf again, and to be back in this position, can't get the smile off my face, so very happy."