World No. 1 Jon Rahm of Spain birdied three of his last four holes on Thursday to pull into a tie for first place at the midpoint of the Farmers Insurance Open in California.
Rahm (65) moved to 13 under and joined Justin Thomas and Adam Schenk, who went even lower than Rahm with a 63 and 62, respectively.
All three co-leaders played the North Course at Torrey Pines for their second round after opening the event at the South Course. The trio leads Cameron Tringale (65 Thursday) by a shot and Peter Malnati (66) by two.
After starting on the back nine of the Torrey Pines North Course with five birdies and a bogey, Rahm avoided bogey the rest of the day while birdieing the sixth through eighth holes en route to a 7-under day.
Rahm won the tournament in 2017 and returned to Torrey Pines to lift his first major championship trophy at last year's US Open. He said those experiences weren't comparable to his situation this week because he won those events from behind.
"A US Open is very, very different. I believe I was 3 under through two rounds and I was thrilled with that score," Rahm said. "At (13) under right now and I think how much better it could have been if I hit fairways, right? So it's not comparable."
Thomas, a major champion like Rahm, is in search of his first title since the 2021 Players Championship 10 months ago. He rattled off nine birdies without a bogey Thursday to shoot five strokes lower than his opening round.
Among his highlights was a chip-in birdie that swept right to left at the par-4 second hole. Thomas said it was his first chip of the day.
"These greens don't quite grab as much on the chips and the pitches, so unfortunately I hit it well to the first 10 holes where I hadn't hit a chip yet," Thomas said. "So I tried to remember it's the same as the chipping green, tried to kind of remember some of that and just felt like the 57-degree (wedge) was a little better option, and it was."
Though he doesn't have the notoriety of his fellow co-leaders, Schenk did Thomas one better: a bogey-free 62 with 10 birdies, including eight straight from Nos. 4-11. The score marked a career low for the 30-year-old, who's still hunting for his first PGA Tour win.
The final birdie of his run came from off the green at the par-4 11th. Schenk judged it at about 30 feet.
"Honestly, I lost track of how many I made in a row. I knew it was a couple obviously," Schenk said. "I had done it before, obviously not on the PGA Tour, on this stage. I just lost track and knew I had some par 5s coming up and wanted to take advantage of them."
Alex Smalley matched Schenk's 62 with an eagle at the par-5 17th and seven birdies. He is tied for sixth at nine-under.
Notable names who missed the 36-hole cut of three-under included Bryson DeChambeau, Rickie Fowler, Brooks Koepka and Phil Mickelson.
Jordan Spieth carded a 78 Thursday to finish four-over and miss the cut, ending what was the longest active made-cut streak on Tour at 20 in a row.