Max Homa fired a seven-under-par 65 to join a three-way tie for the lead heading into the final round of the US PGA American Express tournament in California on Saturday.

Homa, chasing the second PGA Tour win of his career after victory at the Wells Fargo in 2019, carded nine birdies to finish the day on 15 under alongside Tony Finau and South Korea's Kim Si-woo.

The 30-year-old Homa might have finished in sole possession of the lead had it not been for a double-bogey six on the par-four seventh on the PGA West Stadium Course at La Quinta, in the California desert near Palm Springs.

That stumble followed a blistering start which had seen the world number 103 reel off four consecutive birdies on the 2nd, 3rd, 4th and 5th holes.

Korea's Kim meanwhile joined the leaders with a bogey-free five-under-par 67.

The 25-year-old from Seoul moved to the top of the leaderboard with a birdie on the 14th, nailing an 82-yard wedge to a few feet before tapping in.

World number 22 Finau was also left ruing a costly double-bogey before staging a late recovery to claim a share of the lead.

The 31-year-old from Salt Lake City, who started the day one off the lead, dropped a shot on the first after three-putting before birdies on the 4th, 5th, 7th and 8th holes left him three under by the turn.

A further birdie on the 11th took Finau to four under but he came unstuck on the par-three 13th when his tee shot plopped into the water alongside the green.

Max Homa blasts out of a bunker on the 18th hole during the third round of The American Express tournament at PGA West in La Quinta, California
Max Homa blasts out of a bunker on the 18th hole during the third round of The American Express tournament at PGA West in La Quinta, California GETTY IMAGES NORTH AMERICA / Sean M. Haffey

That mistake led to a double-bogey five but Finau bounced back brilliantly to reel off three straight birdies and join the leaders.

A 91-yard approach shot to three feet set up a birdie on the 14th, and that was followed by another birdie on the 15th, when his 152-yard nine iron from the fairway landed a few feet from the pin.

He was then left with a two-foot birdie putt on the par-five 16th after a deft chip from just off the green.

The leading trio will have little breathing space on Sunday however, with a crowded leaderboard jostling behind them.

A total of 24 players are all within five strokes of each other heading into the final round, with Richy Werenski leading the chasing pack on 14 under.

Werenski moved into contention with a seven-under-par 65 on Saturday to finish the day one off the lead.

Scotland's Russell Knox had the lowest-scoring round of the day, with a bogey-free, eight-under-par 64.

The 35-year-old from Inverness, chasing his third win on the PGA Tour and his first since 2016, finished with a birdie on the last, rolling in a 13-foot putt.

Knox is on 13 under, two back, alongside Brian Harman and Argentina's Emiliano Grillo.