SAN FRANCISCO (REUTERS) - American Brittany Lang won her first major golf title in dramatic fashion at the US Women's Open on Sunday after her play-off opponent, Anna Nordqvist, was assessed a two-stroke penalty for grounding a club in a bunker.

Following a video review by United States Golf Association officials, Swede Nordqvist was penalised for her actions in a fairway bunker on the second extra hole, the par-four 17th, where her five-iron lightly grazed the sand on her takeaway.

Lang, whose only previous LPGA win came at the 2012 Manulife Financial Classic, ended up winning the three-hole aggregate play-off after making three consecutive pars.

The duo had ended the final round on six-under 282, Nordqvist firing a five-under 67 while Lang closed with a four-birdie 71 at CordeValle Golf Club in the third of the year's five Majors.

South Korean Park Sung Hyun, the second-round leader, bogeyed the par-five last for a 74 to share third place at four under with compatriots Amy Yang (74) and Ji Eun Hee (74) and New Zealand's world No. 1 Lydia Ko (75).

Ko, at 19 aiming to become the youngest golfer to win three Majors, had been two strokes clear with 12 holes to play but her round unravelled with bogeys at the eighth, 12th and 14th, and a damaging double-bogey at the ninth.