Koepka wins US Open, girlfriend steals headlines

The girlfriend of Brooks Koepka has upstaged her US Open-winning partner thanks to a bumbling commentator who mistook her for the golfer's ex.

Koepka bagged his first major championship with a four-shot win over world No.4 Hideki Matsuyama and American Brian Harman at Erin Hills on Sunday.

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The American was celebrating his triumph when girlfriend Jena Sims ran over to embrace him.

That's when things got awkward as commentator Joe Buck accidentally referred to her as American soccer player Becky Edwards, Koepka's former partner.

"Joe, that's actually his new girlfriend, that's Jena Sims," co-commentator Brad Faxon said a few minutes after the mix-up.

Not surprisingly, the hilarious gaffe was pounced upon by fans on social media.

Koepka's actual girlfriend, Sims, is a budding actress and former Miss Georgia Teen USA in 2007.

She's not the first partner to steal the limelight from a US Open winner, as last year's champ Dustin Johnson can attest to.

An over-zealous cameraman made sure most of the headlines would centre around Johnson's then-fiancee Paulina Gretzky, after his questionable filming of her backside.

Koepka's win is expected to see the American climb the rankings to a career-high No.10 in the world.

Overnight leader Harman (72) slumped to a share of second alongside Matsuyama (66), while England's Tommy Fleetwood (72) finished a shot back in fourth at 11-under.

The top-three players in the world - Dustin Johnson, Rory McIlroy and Jason Day - missed the cut for the first time since the rankings started in 1986 and Justin Thomas record the lowest round, a nine-under 63, in relation to par at the US Open, during round three.

But muscular, big-hitting Koepka - who ranks fifth on tour for an average driving distance of 307.6 yards - says the United States Golf Association should give it another chance.

"I thought it was a great test; you had to put the ball in the fairway or you really got penalised, just plain and simple," he said.

The only Australian who made the cut, Marc Leishman, fought back from a five-over front nine - picking up two shots coming home to salvage a 75 and a respectable 27th place.

Jordan Spieth, the 2015 US Open winner, shot a 69 to claw back to one-over.