Gary Woodland opened up a two shot lead heading into the weekend at the U.S. Open Championship but he had a host of European Tour stars chasing him down at Pebble Beach Golf Links.
The American matched the lowest round of the week with a bogey free 65 to get to nine under, with Justin Rose his nearest competition.
South Africa's Louis Oosthuizen was then at six under, a shot clear of Rory McIlroy and Aaron Wise.
Overnight leader Rose carded a second round 70 to extend his advantage and spent most of the day at the top of the leaderboard before Woodland made six birdies, finishing his round with a stunning 50 foot putt for a closing gain.
Woodland failed to register a top ten in his first 27 Major appearances but now has two in his last three after finishing sixth and eighth in the last two US PGA Championships.
"My short game has come around," he said. "I've always been a pretty good ball striker, I've relied on my ball striking on my whole career, athletic ability, but the short game and putting has kind of held me back.
"At the PGA last year I made a lot of putts, especially early in the week. Obviously it was nice to finish in the top 10 and get that monkey off the back."
Rose produced an incredible flop shot on the 11th and bunker shot on the 12th to stay at six under and he was briefly joined at that mark by both Wise and Chesson Hadley before an approach to six feet on the 15th brought a birdie and a two shot lead.
He got up and down from the sand on the 18th to lead by three at the turn but found rough off the tee on the next and saw his par putt take a full horseshoe.
The 38-year-old bounced straight back as he got a nice bounce off the bank at the second and saw his approach roll to four feet but he found the hazard off the tee on the fourth and then missed a short par putt.
"No expectations for the weekend, really," said Rose. "I like my position, I like the golf course, I like the way I’m trending. I still don’t feel like I’m clicking but if I can find that gear hopefully I can hoist some silverware.
"It’s great being in contention in any U.S. Open but especially here at Pebble. It’s my first here - I missed the one in 2010, in probably some of the best form of my life that year, so it was a tough one to sit at home. It is nice to be in contention."
Rose had a two shot lead when the morning players had finished their rounds but Woodland set about cutting that back, putting his tee shot at the 12th to six feet and holing a 17 footer on the 16th.
An approach to eight feet on the first had him in a share of second alongside McIlroy and Oosthuizen and a tee shot to 15 feet on the par three fifth put him in a share of top spot with Rose.
The 35-year-old then got on the par five next in two to set up a birdie and take the lead before his big finish.
Oosthuizen birdied the first and bogeyed the fifth but after taking advantage of the sixth and putting his tee shot to two feet on the par three next, he shared the lead. A bogey followed on the eighth as the 2010 Open Champion turned in 34 before a roller coaster back nine with four birdies and four bogeys,
I still don’t feel like I’m clicking but if I can find that gear hopefully I can hoist some silverware - Justin Rose
Northern Irishman McIlroy nearly drove the fourth and put his tee shot to five feet on the seventh to turn in 33, and looked in cruise control when he holed an 18 footer on the 11th.
But he failed to get up and down from the sand on the 13th and found rough off the 14th tee before hacking out, spinning his approach off the green and finding more bunker trouble for a double bogey.
He bounced back with a stunning shot from a fairway bunker to four feet on the next and he birdied the 16th with a putt from off the green.
American Wise had bogeyed the second but hit the top with birdies on the fifth and sixth before double bogeying the seventh. He then sandwiched a birdie on the tenth with bogeys on the ninth and 14th before a birdie-birdie finish.
England's Matt Wallace matched two time defending champion Brooks Koepka with a 69 and the duo were four under alongside Hadley, Matt Kuchar and Chez Reavie.
Sergio Garcia, Graeme McDowell, Jon Rahm, Xander Schauffele and Henrik Stenson were then in the group at three under.