Tiger Woods endured a frustrating day on Saturday, slipping to four-over after a disappointing 75: The former world No. 1 said: "I struggled on the greens today, quite a bit. They looked quick, but they putted slow. But they were firmer than they were yesterday. So it was a tough tough feel for me to adjust to and it was amazing how all day I kept getting a half club.
"Just one of those days where I was right in between clubs on about every single shot. Just never quite had the right number."
Graeme McDowell moved into a share of the lead alongside Jim Furyk as he carded another consistent round at the Olympic Club. He said: "Obviously delighted with my effort today. Myself and Jim played together the first two rounds, so we'll have the pleasure of one another's company tomorrow.
"It's wide open. I look at guys at 2 and 3 and 4 over par in this tournament, who I really think they have a realistic shot to win tomorrow. There's a fine line in this golf course between 67, 68 and 75, 76.
"I was happy that I got myself emotionally in the right place today. Probably for the first time this week actually enjoyed the round of golf. It was quite nice out there."
Jim Furyk has impressed in each round of the tournament, and heads into the final day with a chance to break clear of the field. The 2003 US Open winner said: "The first six holes were tough. Those red scores disappeared very quickly early on in the round today and a bunch of guys got over par early and it seemed like a couple of us were able to come back and play pretty well for the last 12 holes and make a good round out of it.
"I got off to a little slow start being 2‑over for six. And didn't feel like it was that bad, seeing looking up at the board and seeing the rest struggling. But I kept myself in good position."
Lee Westwood remains in contention after shooting the round of the day to move to within three strokes of the leaders, saying: "I had a lot of fun out there. Really enjoyed the day. Finished it off nicely. A lot of good chances to shoot a really good score out there. But obviously a 67 isn't a really low score, but I had a couple good chances at 16 and 17 that I didn't birdie and then I made the last bomb at the last that you don't expect. So it was a good way to finish.
"I think I've probably been this contention in major championships more than anybody else over the last three or four years. So I'm looking forward to tomorrow and hopefully going to go out and have some fun and see what happens."
Fredrik Jacobson is in outright second, two strokes behind the leaders. He said: "I knew before the round that if I could put a good number up today that I most likely could give myself a chance for tomorrow. It was a big day out there today to try to close the gap a little bit and get into contention."
Phil Mickelson found little time to celebrate his birthday as he slipped to eight-over. A frustrated Mickelson said: "It's a long, difficult day, even though it's my birthday. And it was very flattering of the fans [to sing Happy Birthday], thank you."
Englishman Justin Rose is an outside chance at five-over and is hoping the tricky San Francisco course will do him a favour on Sunday. He said: "It's certainly bunching up looking at the leaderboard there. Probably 35 guys within six of the lead or something like that. So this venue has a reputation of being a heart breaker. And the more guys you have in the chasing pack, the more likely that's going to be tomorrow.
"I'd like to be one or two better, but I'm still thereabouts. If I can shoot a great round of golf, probably 66, post it, you never know."
Beau Hossler impressed in his even-par round. The 17-year-old was understandably pleased with his efforts, saying: "I had a great day. I went out there and didn't really have any expectations except for to make sure that I'm getting the most out of my round like I've been saying. I got off to a pretty good start.
"Fortunately I heard from somebody that I had four bogeys but packed all of them up with a birdie and that really helped me to keep my round going."