Brooks Koepka endured his first sign of a wobble at Bethpage Black this week but was still firmly in control of his own destiny at the US PGA Championship.

The American recorded-back-to-back bogeys at the ninth and 10th holes, which meant he was back to level par for the round and 12 under for the tournament.

Koepka was two under through eight thanks to birdies at the third and fifth holes, the latter thanks to a sensational approach shot to within three feet, and he had several other looks on the front nine.

Jazz Janewattananond was six shots back of Koepka, while world number one Dustin Johnson was a further stroke adrift having reached seven under at one stage.

Jordan Spieth and Adam Scott, who started round three as Koepka's nearest challengers, were two and three under for the tournament respectively.