Spieth, Koepka set the pace at windy Birkdale

Golf - The 146th Open Championship - Royal Birkdale - Southport, Britain - July 20, 2017 USA’s Jordan Spieth hits a putt on the third green during the first round REUTERS/Andrew Boyers

SOUTHPORT, England (Reuters) - Americans Jordan Spieth and Brooks Koepka tamed a fiendish links course to fire impressive 65s and lead the field by two shots, midway through the British Open first round at Royal Birkdale on Thursday.

Spieth, world number three and twice major champion, putted smoothly to pick up five birdies and did not drop a shot after fierce crosswinds buffeted the early starters.