Adam Scott went from one off the lead to 10 shots off the pace after a marathon morning in the US Open at Merion Golf Club.

The Masters champion restarted his rain-interrupted first round at three under par through 11 holes but was 10 over through the next 25 holes as he completed round one and pushed on to round two.

It left the Queenslander at seven over par thanks to rounds of 72 and 75, 10 shots adrift of Phil Mickelson’s first-round lead.

Tiger Woods and Rory McIlroy shot 73 in the morning round to be behind Scott but backed it up with matching 70s to be three over and well in contention.

With conditions exceptionally tough, Scott is still expected to make the weekend as the afternoon wave of players head out on course.

“I struggled with my rhythm all day and didn’t make the putts I needed to,” Scott said.

“I was a little out of sorts and fought with it all day.”

Jason Day is now the leading Australian, heading off in round two at even par.

John Senden sits in the clubhouse at one over after finishing with a stylish 70 in round one and a grinding 71 in round two.

Only American Billy Horschel, who tied a US Open record by hitting every green in regulation and shot 67, and England’s Luke Donald sit above Senden in the clubhouse.

Horschel is one under while Donald is even par through two rounds.

Mat Goggin backed up a great 68 in the morning with a 74 to be two over par and inside the top 20.

Geoff Ogilvy ground hard for a 70 to remain four over following his morning 74 and Alistair Presnell will be sweating the cut line after finishing at eight over, but the US Open appears over for Marcus Fraser (+12) and Marc Leishman (+13).

Aaron Baddeley starts round two at five over par.