LOS ANGELES: Sam Burns birdied the last three holes to seize a two-stroke lead over fellow American Max Homa and England's Matthew Fitzpatrick and after Thursday's opening round of the PGA Genesis Invitational.

Burns, a 24-year-old chasing his first tour victory, fired a seven-under-par 64 at Riviera Country Club for his third top-four start in his past four starts.

"I think just being patient out here (is key)," Burns said. "This golf course at times doesn't offer you a lot of opportunities, so I think just with that mindset going in we were just going to kind of take what we could get."

Fitzpatrick matched his best US PGA first round with a 66 to equal Homa in second with a pack on 67 including Sweden's Alex Noren, Australian Matt Jones, Chile's Joaquin Niemann and American Patrick Cantlay.

"Really pleased," Fitzpatrick said. "To get off to a start like that in the first round, I'm delighted."

Burns eagled the par-5 first hole on a 19-foot putt and birdied the fifth then answered a bogey at the par-3 sixth by dropping his approach inches from the cup for a tap-in birdie at the par-4 seventh. He closed the front nine with a 16-foot birdie putt.

World number 147 Burns took a bogey at 12 after finding a greenside bunker but birdied 13 and then reeled off his fantastic finish -- a birdie putt from just inside 20 feet at the par-3 16th, another frpom 10 feet at the par-5 17th and a final birdie at 18 after leaving his approach within four feet of the hole.