Bryson DeChambeau said a two-shot British Open penalty "fires me up" as Ryan Fox became the third player in two days to equal the record score of 62 at a major to move into a share of the lead on Saturday.
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DeChambeau thought he had climbed to within one shot of the lead with a birdie-birdie finish to his second round.
But with dark descending on the Southport links on Friday night, the American was handed a two-stroke penalty for "inadvertently improving" his lie as he addressed his second shot at the fifth hole.
DeChambeau appeared to trample down long grass as he addressed his ball for a practice swing.
The two-time US Open champion travelled back to the site of the incident with a rules official after completing his round, and Sky Sports reported he had even threatened to withdraw from the tournament.
However, DeChambeau is back for the weekend after making the cut for the first time at a major this year.
"Obviously disappointed with the ruling. I don't agree with it, but it is what it is. This fires me up. Onto the weekend. Let's get it," DeChambeau, who avoided interviews after his second round, posted on social media.
Mark Darbon, Chief Executive of tournament organisers the R&A, said the decision was "really clear-cut from a rules perspective."
Darbon refused to confirm whether DeChambeau had suggested he could pull out of the final two rounds.
"It's fair to say there was some emotion around that and we will keep some of the aspects of that discussion private," Darbon told the BBC.
"I empathise with that. Bryson has played a great round of golf, is in contention at a major championship, he wants to win golf's original major.
"We were focused on the ruling and making a fair assessment."
Instead of teeing off alongside leader Lucas Herbert in the final group, DeChambeau will begin three shots off the lead in the third-to-last group with fellow American Sam Burns.
STACKED LEADERBOARD OF STARS
Herbert and Burns both equalled the all-time record low score for a round at a major championship on Friday by carding a 62. New Zealand's Fox followed suit to join Herbert at the top of the leaderboard on eight under par.
Until yesterday, there had only been five rounds of 62 in major history, but there are now eight, made by seven different players.
After six birdies in the opening 10 holes, Fox's shot at a historic 61 was undone by a bogey at the 13th.
He bounced back with three birdies in the final five holes to climb into contention going into Sunday's final round.
A leaderboard packed with some of golf's biggest stars is primed for a spectacular weekend in pristine conditions on England's north-west coast.
Cameron Young, world No 4, begins his third round at six under.
World No 1 and defending champion Scottie Scheffler is two shots further back but well in the running at four under, alongside home favourite Tommy Fleetwood and two-time major winner John Rahm.
Rory McIlroy's hopes of making a charge up the leaderboard appeared to be fading as he was one over for the day through eight holes to slip to level par for the tournament.
But a monstrous drive and chip in for eagle at the par-four ninth brought the Masters champion back within six shots of the lead at the turn.