WATCH: Phil Mickelson Four Putts At US Open

Phil Mickelson made his long-awaited return to Major championship golf at the US Open but his attempt to complete the career grand slam got off to a nightmare start.

Lefty found himself five-over-par after six holes in round one, courtesy of three bogeys and a double bogey, with the double featuring a disastrous three-putt from within 12ft.

Mickelson found the green at The Country Club's par-3 6th with a good birdie chance to get back to two-over, but four putts later he found himself at five-over and already at risk of missing the cut.

Watch Mickelson's four putt:

He dropped to six-over-par after 10 holes but thankfully for the American, who turned 52 on Thursday, he made his first birdie of the day at the 11th.

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Mickelson said last week's LIV Golf Invitational Series opener at the Centurion Club was one of his worst putting tournaments of his career and he spent plenty of time practising with the flat stick in Brookline prior to the start of the tournament. He is clearly still quite rusty after his four month break away from the game, ranking 155th in strokes gained putting out of the 156-man field.

The six-time US Open runner-up has only missed four cuts in his national open since 1990 but he looks set to have some work to do on Friday to avoid missing the weekend for the fifth time.