The South Korean did not drop a shot all round and made four birdies in the final five holes to pull further clear of the field and win by five shots at Aronimink Golf Club in Pennsylvania.

Kim held a two-shot lead overnight, but both Brooke Henderson and Anna Nordqvist, who were tied for second place after 54 holes, had over-par final rounds.

Swede Nordqvist and Canada's Henderson are both past winners of the Women's PGA Championship, but ended 10 and 11 strokes behind Lee respectively in fifth and sixth places.

Park Inbee, the reigning Olympic champion and a three-time winner of this event, came second at nine under.

Park produced a bogey-free 65, but even that saw her lose ground to compatriot Kim.

Japan's Nasa Hataoka, 21, also had a bogey-free round and an opening-hole birdie put her en route to a 64 and a tie for third place.

Carlota Ciganda of Spain, who shot 65 today, shared third place with Hataoka. 

This win is the biggest of Kim's career - she had previously won 10 times on the Ladies Professional Golf Association (LPGA) Tour, to go with five LPGA Tour of Korea victories.

A second-place finish at the 2015 Women's PGA Championship, won by Park, was her previous best at a major.