Rookie targets Rahm in PGA Tour last round

Impressive American rookie Davis Thompson is relishing a final-round showdown with in-form world No.4 Jon Rahm as he chases a maiden PGA Tour title.

The pair are tied at 23-under with a four-shot gap to their closest challengers after keeping up a hot pace at The American Express tournament in the Californian desert on Saturday.

A Tournament of Champions winner two weeks ago, Spanish star Rahm shot a seven-under 65 PGA West's Stadium Course.

The 23-year-old Thompson's run of five eagles in two rounds ended as he carded a 67, also on the Stadium Course, just missing a 35-foot birdie putt on No.18 that would have given him a one-stroke lead.

Rahm and Thompson will make up the final group on Sunday on the Stadium Course, which was one of three courses that hosted the first three rounds.

J.T. Poston (66) and South Africa's Christiaan Bezuidenhout, who shot a 10-under 62 on the Nicklaus Tournament Course, were tied for second, four strokes behind the leaders.

Tom Kim, Harry Higgs, Sam Burns and Taylor Montgomery were another stroke back at 18 under.

"Nothing but positive," said Rahm, who will be playing for his ninth tour victory. "Ball-striking felt amazing.

"So very confident going into tomorrow and knowing that I'm going to have to shoot another low score if I want to have a chance to win."

The resilient Thompson was up for the challenge on Sunday.

"It's great. I feel like I don't have anything to lose in my rookie year," Thompson said. "Just kind of freewheel it. But I'm excited to play with Jon. He's obviously a top 5 player in the world. He's very good."

Second-ranked Scottie Scheffler was in a group of six at 17 under.

Australia's former world No.1 Jason Day could not stick with the hot scoring pace, shooting a two under 70 on the La Quinta course to fall from tied third to tied 16th, eight shots behind the leaders.

Rookie countryman Harrison Endycott was two shots further back after a 67 while Cam Davis missed the third-round cut set at 10 under by seven shots after a 70.