Rahm, ranked No. 3 in the world, is 18 holes away from potentially winning his third straight start and taking over at No. 1 for the first time since March 20. He began Friday at 4 under and tied for 14th, and moved into sole possession of second place after an eagle on the par-5 ninth hole that capped his second stretch of playing four holes in 5 under in two days.
While Rahm heated up on a gorgeous, calm day on the municipal course overlooking the Pacific Ocean, Ryder parred his last 12 holes for a 72, missing a 10-foot birdie putt on the par-5 18th. Ryder was at 12-under 204 through 54 holes while Rahm was 10 under.
Tony Finau, 12 shots back when he started his third round on the back nine, turned in 4-under 32 and then holed his approach from 138 yards on the par-4 first hole for an eagle. He shot an 8-under 64, the best round of the week on the South Course, to move into third place, four shots back.
Sungjae Im eagled No. 18 for a 67 and was five shots back along with Collin Morikawa (70), Max Homa (71) and Sahith Theegala (71).
The tournament has been played from Wednesday to Saturday the past two years to avoid having the final round go against the NFL's conference championship games.
It's been an adventuresome three days for Rahm at Torrey Pines, where he earned his first PGA Tour victory in 2017 and then won the U.S. Open in 2021 for his first major.
Rahm said Torrey Pines has been his favorite venue since "before I ever did anything, really. This is a wonderful golf course. It obviously suits my strengths and I think because I like it so much I've done very well here."
Rahm was tied for 116th after playing the opening round at 1-over 73 on the South Course. He was one off the cut line with five holes left in his second round on the North Course in Santa Ana winds on Thursday before making an eagle and three straight birdies. He has played his last 23 holes in 11 under.
The Spanish star played the front nine on the South Course, which hosts the final two rounds, in 5-under 31 on Friday thanks to three straight birdies and then the eagle on 9.
He said his second shot on the ninth, a draw from 289 yards, "was contender for best shot of the year for me already. I was just hoping to catch it on the center of the green, but I mean, I tattooed that 5-wood and ended up having 10 feet for eagle, which you don't really expect on that back pin, but I ended up putting myself in a great situation and made the putt.
"I'm a very aggressive player by nature, so nothing really changes," said Rahm, who won the Sentry Tournament of Champions at Kapalua three weekends ago and The American Express in the Coachella Valley last weekend. "I kind of stay true to who I am and the difference between that and the next four holes was just making better swings at the right time."
Rahm is contending for his 10th PGA Tour victory. Ryder, 33, is seeking his first.
"I'm pretty calm, honestly," Rahm said. "Yeah, there's pressure for obvious things, but I've won my last two tournaments, so I have no reason not to believe that I can do it one more time. I've been swinging it beautifully all week and it just keeps getting better and better so hopefully tomorrow I can do what needs to be done."
Ryder shared the lead with two others after the first round and was up by three strokes after 36 holes.
"Today it's just a different level of pressure," he said. "I didn't feel like I had to go try and make something happen or press, you know, so I didn't panic when I made a bogey on 2 and I kind of just adjusted to the round and kind of got a feel for where I was at with my swing and my game. Starting the day with a lead, ending the day with a lead, pretty satisfied."
