American Brian Harman stormed into a five-shot lead at the British Open on Friday after a faultless 65 left him on 10 under par as bigger names struggled to keep pace.
Harman shot to the top of the leaderboard during his second round at Royal Liverpool thanks to a clutch of early birdies, capping a bogey-free round with an eagle at the par-five 18th.
The world number 26 has never won a major but was sixth at last year's British Open at St Andrews and was joint runner-up at the US Open in 2017.
"I've had a hot putter the last couple of days so try to ride it through the weekend," said Harman.
"I felt kind of freed up on 18. I made probably my two best swings of the day and got up there to 12 to 15 feet for eagle. Just played a really nice hole."
Harman started his second round on Friday one shot off the lead.
He surged to the top of the leaderboard thanks to long birdie putts at the second, third and fourth before his chip into the par-five fifth hit the flag to tee up a simple putt for a four.
A run of 12 consecutive pars followed before his spectacular eagle at the last.
The 36-year-old became the first player to post a clean round on Friday and, barring a collapse over the weekend, he will take some catching, with the pre-tournament favourites struggling to make an impact.
Rory McIlroy is nine shots back heading into the weekend after failing to build on two birdies inside his first five holes.
The Northern Irishman benefited from more forgiving bunkers after tournament organisers reacted to criticism from players that the sand traps were too tough during Thursday's opening round at Hoylake.
Greenkeeping staff were instructed to build up the edges to allow more balls to roll back into the centre of the bunkers.
However, the world number two dropped shots at 10 and 15 before a birdie at the last took him to one under for the tournament.
"I might be nine back, but I don't think there's going to be a ton of players between me and the lead going into the weekend," said McIlroy.
"If I can get to three, four, five-under par tomorrow going into Sunday, I'll have a really good chance."
Masters champion Jon Rahm was one of those to take aim at the bunkers after his frustrating three-over-par opening round.
The Spaniard carded a 70 to leave him at two over, one shot inside the projected cut mark at three over.
Home favourite Tommy Fleetwood leads the pursuit of Harman at five under after a huge birdie putt at the 10th cancelled out an earlier bogey.
France's Antoine Rozner is third on the leaderboard at four-under.
Three-time major winner Jordan Spieth appeared to be making his move with a three-under 32 on the front nine that briefly took the 2017 champion to five under.
But Spieth then bogeyed 10 and 11 to fall back to seven off the lead.
Australia's Min Woo Lee and Indian Shubhankar Sharma share the second-best score in the clubhouse on three under.
Brooks Koepka remains the biggest threat if the Claret Jug is to be lifted from the group of players now regularly plying their trade in the Saudi-backed LIV Golf series.
The five-time major winner moved to two under at the halfway stage of his second round thanks to a bridie at the fifth.
World number one Scottie Scheffler fell back to level par through nine holes, while defending champion Cameron Smith is at one over.
Climate protestors from the Just Stop Oil group targeted the tournament on Friday, setting off a smoke flare and throwing orange powder onto the course.
American golfer Billy Horschel intervened to help remove one demonstrator at the 17th hole.
Police confirmed four people had been arrested on suspicion of conspiracy to commit criminal damage and public nuisance.
British golf's landmark tournament is the latest high-profile sporting event to be targeted in recent weeks following interruptions at Wimbledon and during the second Ashes cricket Test at Lord's.
