Casey joins Johnson at top in congested US PGA title tussle

The competition at the top of the US PGA Championship leaderboard showed little sign of dispersing as Dustin Johnson had Paul Casey for company at the summit through nine holes.

Overnight leader Johnson held a one-stroke advantage heading into Sunday’s final round as he aims to add to his sole prior major triumph at the 2016 U.S. Open.

But a number of stars were in hot pursuit and, despite a birdie at the first, Johnson failed to pull clear of the chasing pack before the turn.

A bogey at the third opened the door a little wider for those with serious title interests, but the former world number one bounced back at the next to return to 10 under.

Casey was there, too, by the time Johnson reached the ninth, though, building on scores of 68, 67 and 68 with birdies at the fourth, fifth and 10th.

Cameron Champ and Bryson DeChambeau had each earlier moved into position to challenge the frontrunner.

Champ – a 25-year-old with just two PGA Tour wins to his name – joined Johnson on 10 under and put away a vital 18-foot putt for par at the eighth, but he left himself with an awful lot to do at the following hole and fell two strokes off the pace.

Meanwhile, DeChambeau spectacularly lost momentum just as he briefly pulled level with Johnson, back-to-back bogeys undoing his hard work.

A clutch of others were also in contention, however, with impressive consecutive birdies following the turn giving Jason Day a share of third, one shot back.

Tony Finau, Collin Morikawa and Scottie Scheffler were all also on nine under.

Matthew Wolff had been among the same throng following a rapid ascent up the leaderboard – managing three straight birdies from the seventh, then adding an eagle at the 10th – but twice missed achievable putts that would have secured a co-lead before falling away.

Much further down the leaderboard, Brooks Koepka’s round was going from bad to worse, with the two-time defending champion falling out of the picture completely.

Having highlighted Johnson’s lack of winning major experience on Saturday, Koepka subsequently struggled from the outset and was four over on the front nine, way back on three under for the week.