It tied the lowest round of the week at Celtic Manor and saw him finish on eight-under par overall and two strokes ahead of Sami Valimaki of Finland, who shot 69.

Sebastian Soderberg, who started Sunday tied for the lead with Connor Syme, went to the par-5 18th needing a birdie to take Langasque to a playoff.

His hopes ended when his approach found the water and he wound up with a triple-bogey eight for a 74, dropping to a tied-for-fifth finish on four under.

Langasque, ranked No.156, was five strokes off the lead when he began his round and made three birdies on both the front nine and back nine.

“Everything in golf can go so quick. I'm really happy, this is where we all want to be.” – Romain Langasque

"Everything in golf can go so quick," Langasque said.

"I'm really happy, this is where we all want to be.

"Playing my first US Open this year, the good thing is with no public there's less pressure on it being my first one. I'm really proud of myself."

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Syme shot 75 to finish tied for eighth on three under overall.

Last week, the Scottish player started the final round of the Celtic Classic – also played at Celtic Manor – with a two-shot lead and finished third.

Unheralded English players Matthew Jordan and David Dixon, who is ranked No.1228, shot 66 and 68, respectively, and were tied for third place.

Jason Scrivener was the best of the Australians and shared eighth place after reaching three under for the tournament.