American Thomas slides after fast start to Open, Noren is clubhouse leader

TROON, Scotland : American Justin Thomas made a strong start at the 152nd Open but then hit trouble as rain squalls kept a grip on the early scoring at Royal Troon on Scotland's Ayrshire coast on Thursday.

Sweden's Alex Noren was the early clubhouse leader with a birdie on the 18th giving him a two-under-par 69 but Thomas initially looked like eclipsing that mark.

The former PGA Championship winner gathered four birdies with one bogey on his outward nine and then birdied the 10th to top the early leader board on four under.

But a double-bogey six at the 12th and a bogey on the 13th dropped him back into the pack.

Fellow American Bryson DeChambeau, last month's U.S. Open champion, started in the company of young Swede Ludvig Aberg, who is ranked fourth in the world, but the big-hitting DeChambeau suffered a terrible start.

He was five over after his first six holes and in danger of playing himself out of contention on day one.

South Korean Song Young-han had made an early move to reach four under but dropped a shot at the ninth and then made a seven on the treacherous par-four 11th while England's Matt Wallace delighted the galleries with a chip-in eagle at the fourth but a triple bogey on the ninth stunted his progress.

Northern Ireland's world number two Rory McIlroy, bidding for his fifth major title 10 years after his last one, began with a bogey at the first after a poor approach shot but birdied the third to get back to level par.

England's former U.S. Open champion Justin Rose, who had to qualify this year, was in a group on two under with Denmark's Nicolai Hojgaard, American Russell Henley and Adam Scott.

Reigning champion Brian Harman uncharacteristically missed a short putt on the first but replied with two birdies to