Patrick Reed of the United States shot an impressive five-under-par 66 to take the clubhouse lead early in the first round of the British Open at Royal Troon on Thursday.

Texan Reed, 25, signalled his intent when he holed his approach shot for an eagle two at the par-four third.

He then added birdies at the fourth, sixth and seventh to reach the turn in 31, but bogeyed the 10th and 13th and did well to come home in level-par 35.

Reed's five-under tally put him a shot clear in the clubhouse from his compatriot Justin Thomas.

Appearing in his first Open championship, 23-year-old Thomas scored an excellent four-under-par round of 67 after beginning his day with birdies at each of the first four holes.

In glorious sunshine but with stiff breezes coming in off the Firth of Clyde, scoring has proven far tougher into the wind on the back nine than on the front nine.

Australian Matt Jones reached the turn on five under par while 2014 Open champion Rory McIlroy stood at four-under after 12 holes.

Source: AFP