|-13 J Thomas (US); -10 B Koepka (US), D Berger (US), T Lewis (Eng), P Mickelson (US)|
|Selected others: -9 S Lowry (Ire), M Fitzpatrick (Eng); -8 D Johnson (US); -3 T Fleetwood (Eng)|
Justin Thomas warmed up for next week’s US PGA Championship by winning the WGC-St Jude Invitational in Memphis.
The American began four shots behind leader Brendon Todd but won by three from Brooks Koepka, Phil Mickelson, Daniel Berger and Englishman Tom Lewis.
Defending champion Koepka birdied 17 to get within one of Thomas but found water on the last to end his hopes.
The closing 65 gave Thomas, the 2017 US PGA champion, his 13th PGA Tour title and a return to world number one.
Koepka bogeyed 16 to give Thomas some breathing space but then made a huge birdie putt on the next to close to within a shot before driving into a stream on 18 on his way to a double bogey.
Thomas’ short game on the back nine was imperious, with a number of world-class pitches and high-class putting combining to make birdies and save par.
Overnight leader Todd struggled throughout and finished the day four over to tie for 11th.
Lewis finished in joint third after he managed to follow up his Saturday 61 with a fine 66.
His compatriot Matthew Fitzpatrick finished joint sixth on nine under alongside Open champion Shane Lowry of Ireland while Tommy Fleetwood was on three under.