The former Shropshire & Herefordshire junior had five birdies in his first 15 holes to move to level par overall, only for two bogeys to let him down in his final three holes.
He finished 17 shots shy of winner Matthew Fitzpatrick, who pocketed the £2.2million first prize
Fitzpatrick held his nerve as an incredible late twist saw Lee Westwood win the Race to Dubai.
Fitzpatrick secured the first prize of £2.2million thanks to a closing 68 which left him 15 under par and a shot clear of Westwood, with Patrick Reed and Viktor Hovland another stroke back.
Outright second was enough for Westwood to pip Fitzpatrick to the Harry Vardon Trophy by just 17.8 points, with long-time leader Reed pushed down to third place. Westwood had set the clubhouse target, but at the time only shared second with Laurie Canter to leave Fitzpatrick on course to top the money list.
However, Canter made a double bogey on the 17th and was unable to deny Westwood a third Order of Merit title.