Justin Rose will take a one-stroke lead into the third round of the Farmers Insurance Open, after carding a one-over-par 71 on the South course at Torrey Pines.
The 36-year-old Englishman offset back-to-back bogeys on the back nine, with three birdies to retain his slender advantage from day one.
Rose, who opened with a 65 on the much easier North course on Thursday, hit 14 greens in regulation in round two and, at the halfway stage, his nearest challengers are Adam Hadwin and Brandt Snedeker.
In seven previous visits to San Diego, Rose has failed to finish inside the top 20 and he believes anyone who made the cut still has a good chance of winning the event.
He said: "I was going along really nicely and playing lovely. I think I hit my first 10 greens in regulation and felt like I was in control.
"But this golf course gets tough as you turn back into the breeze there on 14, 15, 16 and it was really nice to finish with a birdie on 18.
"It felt like, as we turned into the wind, the greens got bumpy too. So it was even hard to see pars coming in. I actually think the cut mark [level par] is incredibly low for two days around here.
"Pretty much everyone who's made the cut is still in the tournament."
Second place Hadwin, who fired 59 last week en route to finishing second at La Quinta, actually played better on the South course which he covered in 66 strokes on Thursday.
Over the opening two days the South course averaged 73.8 but, on Friday, Hadwin could only shoot 71 on the North.
Hadwin stressed: "I played really well last week as well and I was in contention and gave myself a chance to win that golf tournament.
"This is probably the best golf I've been playing in my career and it's just a matter of staying patient. Just go out and hit some fairways, give yourself some looks and you'll have a chance."
Alongside Hadwin, one stroke off the pace, is defending champion Snedeker, who is chasing a third victory on the clifftops of southern California.
The American has posted rounds of 68 and 69, the latter on the South, which included six birdies and three bogeys.
And there were some big names casualties on Friday with Jason Day, Dustin Johnson and Tiger Woods all missing the cut.
The trio were playing in the same threesome on the North course but will not be returning for the two weekend rounds over the South.
World No 1 Day fired 73-74 to miss out by three strokes, reigning US Open champ Johnson was one shot better after rounds of 72 and 74, while Woods went 76-72 and will now travel to the Middle East for next week's Dubai Desert Classic.
An upbeat but realistic Woods, who was playing in his first official PGA Tour event since August 2015, said: "I hit a lot of beautiful putts that didn't go in. But I hit it a lot better today which was nice.
"Playing tournament golf is a bit different to playing with your buddies in a cart. I need to get more rounds under my belt and more playing time and that's what I'm trying to do."