Rory McIlroy birdied the three par-fives with a sensational combination of power and guile. But while he was solid on the greens for most of the day, Riviera Country Club's poa annua surfaces became bumpier late in the day and cost the world No 3 some crucial shots.
"I think it was sort of a tail of two nines," McIlroy said after a two under 69 left him four behind Jason Kokrak (68-64) and in an eight way tie for seventh on six under. "I played the front nine very well, very solid, 3-under par. I think for me, that's the more difficult nine on this golf course.
"And the back nine was a little scrappy. The bogey on 10, which you can do here, I mean, it's a tricky golf hole. I sort of put myself out of position. But bogey from the middle of the fairway at 13 and then to 3-putt 15, as well. Sort of two unforced errors there. I can't make those going into the weekend, if I want to have a chance to win."
McIlroy mix fives birdies with three bogeys as Pádraig Harrington made his third bogey of the day at the 18th to sign for a one under 70 that left him tied 51st on one-under 141.
The Dubliner had a better day on the greens but a bogey-birdie-bogey finish was not quite what he was looking for.
McIlroy got off to another perfect start, two-putting the par-five first for birdie before holing a near 60 footer for another birdie at the third.
Apart from an 11 footer at the seventh, he was always putting from long range but he managed to sneak one at the ninth, holing a 26 footer straight up the hill to turn in 32.
With two birdies chances to come, he looked set to challenge for the lead but after hitting his tee shot left at the driveable 10th, he semi-fluffed his 52 yard second and took three more to get down from 18 yards away.
He made amends at the 11th, screwing a 70 yard third back to a couple of feet. But he then bogeyed the 13th after overshooting the green, missing a seven footer, and then three-putted the 15th from 27 feet to fall back to one under for the day.
Irritated by those mistakes, he flexed his muscles at the 17th with a cut, 312 yard drive and a bombed, 285-yard three wood to the middle of the green.
Two putts yielded another birdie and he then had to show his imagination at the 18th, cutting his approach from the right rough to the back of the green.
He was careful with his par putts from a couple of feet at both the 17th and 18th as the surfaces became bumpier late in the day.
"Rectified it a little bit with the two birdies on the back nine and the par 5s, but just need to get off to a fast start tomorrow, get myself close to the leaders and play a good, solid round and see where that puts me going into Sunday," added McIlroy, who is one behind sixth placed Marc Leishman and in an eight way tie for seventh with Kyle Reifers, Justin Leonard, Adam Scott, K.J. Choi, Hideki Matsuyama, Charl Schwartzel and Luke List
On the greens, he added: "I don't know if you could see on the telecast but the greens were getting very bumpy out there. I think more than anything else, because of the low sunlight, you could really see it.
"And especially with some of the -- even the 15- and 20-footers that you were leaving yourself, you didn't really want to race them by too much, because those 3- and 4-footers are very, very tricky here.
"So I felt I held a few good putts today. I missed a couple, as well, particularly on the back nine. But yeah, I think with less traffic over the weekend and not as many guys, hopefully they will be a little bit smoother for us.
Even on the back nine there, if I lagged a putt up within 18 inches, I was still marking it. Sort of going, 'You go ahead, I'll take my time on this one.'
"It is a fine balance. I think that it's all to do with your approach shot. If you can leave the ball below the pin here and give yourself uphill putts, it makes it a hell of a lot easier."
Kokrak leads by one on 10 under par from Chez Reavie (67) with Dustin Johnson (66), Troy Merritt (66) and Bubba Watson (68) tied for third on eight under but McIlroy appears to be relishing his first trip around Riviera.
Q. How many times have you gone to a course on word-of-mouth and it lived up to your expectation? Does that happen a lot?
RORY McILROY: Not a lot. I'd say here, Augusta, Shinnecock. Yeah, I'm looking forward to seeing Oakmont this year. I've heard a lot of good things about there. Yeah, I do like it here, I really do.
Q. Did you like it immediately?
RORY McILROY: Yeah, and I don't feel like I have to play really good to still shoot a score. It's that sort of golf course, if you can limit your mistakes and play solid golf, it's there to score. It's a fun golf course. It's just fun to play. It's nice that there's basically no hazards on the golf course, and it's tree-lined. I like golf courses like that. Sort of like an Akron-type of thing, where not many hazards, but if you hit it off-line or if you put yourself in the wrong position, you're going to get punished for it.