LOS ANGELES (AFP) — American Sam Ryder defied gusting winds at Torrey Pines on Thursday to fire a four-under par 68 and push his lead to three strokes in the US PGA Tour Farmers Insurance Open.

Ryder, who shared the overnight lead with England's Aaron Rai and fellow American Brent Grant, had five birdies on the South Course for a 12-under par total of 132 — three strokes clear of playing partner Brendan Steele.

Steele, who started the day one off the lead, closed with back-to-back birdies in a two-under par 70 for a nine-under par total of 135.

"It feels great," Ryder said of taking the lead into the weekend in search of his first US PGA Tour title.

"The thing I've been kind of telling myself is to just try and embrace it. It's not a position that I've been in a lot, you know, so just trying to enjoy it."

Ryder followed a two-foot birdie at the third with a bogey at the fourth, where he was in a fairway bunker and a greenside bunker.

He rebounded with an eight-foot birdie at the fifth, and rolled in a six-footer at the 10th, a 10-footer at the 13th and a 12-footer at 14.

"I'm just doing everything pretty solid," Ryder said. "Starts off the tee for me, I'm driving it well. My iron play is really good, so I feel like if I put it in the fairway, I can attack. And I don't think I really missed many shots today.

"I feel like I had a couple nice bunker saves, things that you have to do to keep rounds going especially on a tough day like this, where it's windy around a tough course," added Ryder, who led by as many as five before Steele cut the deficit with his birdie-birdie finish.