After three solid rounds at the PGA Championship, Kiwi golfer Ryan Fox went backwards in the final round to slip outside the top 50 in his opening major of the year.

Following three even par rounds of 70, Fox went into the final round in a share of 23rd place but a seven-over 77 saw him drift down the leaderboard at Southern Hills.

Fox had two bogeys on the front nine and a further five dropped shots on the back nine to finish at seven-over for the tournament in 54th place.

Justin Thomas took out the title after defeating Will Zalatoris in a three-hole playoff.

Fox will still take home US$29,250 ($45,675) from the week as he now jets back to Europe for the KLM Open in Netherlands this weekend.