By Martyn Herman

SOUTHPORT, England, July 19 (Reuters) - New Zealand's Ryan Fox birdied the 18th hole at Royal Birkdale to win a thrilling 154th British Open by one stroke on Sunday.

Fox was level with long-time clubhouse leader Cameron Young on nine under heading down the last but played a stunning approach shot and then sank a 20-foot-birdie.

The 39-year-old is only the second New Zealand man to win the Open, following Bob Charles in 1963 at Royal Lytham.

His final-round 68 left him with a total of 270, with Young, who carded a stunning final-round 64, on 271. American Sam Burns, the overnight leader, finished third on eight under par.