Webb Simpson leads US PGA event

Webb Simpson has a two-shot lead over Paul Casey going into the final round of the US PGA event in Texas.

Webb Simpson has a two-shot lead over Paul Casey going into the final round of the US PGA event. (AAP)

American Webb Simpson has carded a three-under-par 67 to earn a two-stroke lead after the third round of the US PGA event in Fort Worth, Texas.

Simpson, the 2012 US Open champion, survived another breezy day to post a nine-under 201 total at Colonial Country Club after a 15-foot birdie putt at the final hole lipped out.

Englishman Paul Casey (68) and South Korean-born New Zealander Danny Lee (69) shared second place on seven under, with Americans Stewart Cink and Kevin Kisner three off the pace.

Defending champion Jordan Spieth and Masters champion Sergio Garcia were five shots behind.

Marc Leishman had a one-under 69 to be even par for the tournament and the leading Australian in a tie for 22nd.