Michael Kim celebrated his 25th birthday a day late as he stayed clear of the field to secure his first PGA Tour victory by eight shots at the John Deere Classic.

The American cruised to victory with a 66 in Sunday's final round to go with scores of 63, 64 and 64, in the process setting a new record of 27 under par for the tournament at TPC Deere Run in Illinois.

Kim carried a five-shot lead into day four and having birdied five of the last six holes on a rain-interrupted Saturday, did the same at the first three on Sunday before adding a fourth at the eighth to go out in 31.

A run of seven successive pars around the turn ended with a birdie two at the 16th, and two further pars saw him home in some comfort.

Italy's Francesco Molinari was among his closest challengers as he carded a seven under 64 to finish in a tie for second at 19 under with Joel Dahmen, Sam Ryder and Kim's playing partner Bronson Burgoon.

Burgoon teed off at the final hole needing a birdie to claim second in his own right, but having found a green-side bunker with his second shot, played out to within inches to ensure his share of the spoils with a 69.

Ireland's Seamus Power tied for a share of 16th over all after his final round of 69 left him on -14 for the tournament.