Adam Scott has recorded his best 36-hole start to the US Open but insists he can hit another gear in the weekend rounds while chasing leader Justin Rose at Pebble Beach.
Scott posted two opening rounds under par for the first time in his US Open career - his two-under-par 69 on Friday backing up a Thursday 70.
He sits at three-under the card and four strokes behind current leader Rose (65, 70).
Scott had only recorded six total rounds under par in his 17 previous US Open appearances.
But the 38-year-old has managed to take advantage of a soft Pebble Beach, offering competitors plenty of scoring opportunities.
On Friday in California, Scott bogeyed his first two holes which he says put the pressure on early and did not allow him freedom to attack.
The former world No.1 hit a solid 13 greens in regulation but three bogeys prevented him from climbing further up the leaderboard.
"After that I felt I really needed to get it on track, or I'd miss the cut if it went the wrong way," Scott said.
"So I was left hedging my bets on a lot of shots; playing very smart and safe and maybe not able to take advantage of how I'm really swinging it."
Scott, who finished second in his most recent US PGA Tour event, said his swing is feeling as good as it ever has and is confident of low scores in the third and final rounds.
"It's really good stuff, but it just doesn't feel like I'm opening up yet," Scott said after his round.
"There was lots of good stuff and hopefully I can find that nice rhythm at the weekend.
"I feel I can close that gap (on the lead) quickly in an hour or so at the weekend and I'll be there right in the mix.
"I'm also very patient; it's one of my strong suits and you can chip away at a US Open."