Amy Yang is tied for the lead at the Women's PGA Championships ©Getty Images

South Korean duo Amy Yang and Chella Choi are tied for the lead at the KPMG Women's PGA Championships as weather affected the opening day of play at Olympia Fields Country Club in Illinois.

Yang, twice a major runner-up at the United States Women's Open, bogeyed the 17th hole to drop to five-under.

As a result she surrendered her sole lead just moments before lightning prompted the afternoon's play to be suspended.

Yang is among 30 players who are now due to complete their opening round tomorrow morning.

Choi managed to complete the full 18 holes as she birdied four of the last six to post a five-under 66 at the second major of the year.

Brittany Altomare of the US shot a 67 while France's Joanna Klatten joins her at four-under with two holes still to complete.

American Michelle Wie is among a group of six on three-under, which includes defending champion Brooke Henderson of Canada.

Chella Choi managed to complete her round before the bad weather arrived ©Getty Images
Chella Choi managed to complete her round before the bad weather arrived ©Getty Images

South Korea's Ryu So-yeon, who became world number one last week, is among a congested list of 12 players on two-under.

Former world number one Lydia Ko of New Zealand is a shot further back.

Great Britain's Laura Davies, winner of this tournament in 1994 and 1996, endured a poor start after hitting six bogeys and a double bogey in her opening nine holes.

However, she steadied her round on the back nine to finish seven-over.

The final round is due to take place on Sunday (July 2).