LOS ANGELES (Reuters) - Canadian Brooke Henderson won her first major title on Sunday after beating Lydia Ko in a play-off at the KPMG Women's PGA Championship in Sammamish, Washington.

Henderson, 18, sank a three-foot birdie at the first extra hole, the par-four 18th, after firing an exquisite approach shot to near tap-in distance.

She prevented New Zealander Ko from becoming the youngest woman to win three consecutive major championships.

Henderson carded a closing round of 65 to catch Ko (67) at six-under 278, one stroke ahead of Thailand's Ariya Jutanugarn (66), who was going for her fourth straight Tour victory.