Brian Harman leads the US Open by one shot.
Brian Harman leads the US Open by one shot. Chris Carlson

Harman in front on crowded US Open leaderboard

AMERICAN Brian Harman has taken a dramatic third round by the scruff of the neck to lead the US Open at Erin Hills in Wisconsin.

American Justin Thomas became the 29th golfer to shoot 63 in a major championship.

But with debut host course Erin Hills yielding to scores not typical of a US Open, Thomas couldn't hold the lead for more than an hour as Harman came in with a five-under-par 67 during the third round.

Harman, who won the US PGA Tour's Wells Fargo event in May, climbed to 12 under and will take a one-shot lead into the final round over world No.13 Thomas, Brooks Koepka and England's Tommy Fleetwood (both 68) sharing second place.

World No.9 Rickie Fowler, who held the halfway lead, earned solo fifth with a 68, with Players Championship winner Si Woo Kim a shot back alone in sixth after also carding a 68.

Earlier, Thomas mixed nine birdies and two bogeys before hitting his second shot to six feet on the par-5 18th and tapped in for eagle to record the lowest round (nine under) in relation to par in US Open history.

Johnny Miller shot 63 at the 1973 US Open but it was at the par-71 Oakmont, with this week's venue Erin Hills being a par-72.

Robert Streb was the last golfer to shoot 63 at the majors during the 2016 US PGA Championship.

Thomas, who has three wins already this season, is chasing his first major victory.

Australian Marc Leishman had raced up the leaderboard through his opening 10 holes before a double bogey at the par-4 12th saw him let slip a chance to catch the leaders.

The Victorian shot a disappointing even-par 72 to stay at four under, sharing 17th.

Big-names to collapse on day three were former US Open winners Jordan Spieth and Martin Kaymer.

Spieth, who won the 2015 event, dropped away with a 76 leaving him in 59th at four-over while 2014 winner Kaymer fell to even-par after a 75.