Rory McIlory
McIlory barely survives the weekend cut.Reuters

Bubba Watson leads at the half way stage of the Masters seven under par as Rory McIlroy survived the cut by a single shot at Augusta.

The 2011 US Open and 2012 USPGA champion dropped four shots on the back line to shoot 77 and finish four over par having started the day one under.

With 11 shots separating the Northern Irishman and Watson he will need to stage the biggest comeback in the history of the competition and eclipse Jack Burke's eight stroke revival back in 1956.

"It was very frustrating," McIlory said, BBC Sport report. "I just really couldn't get anything to go my way.

"Eleven shots back is going to be nearly impossible to make up."

Watson, who won the competition in 2012, excelled in round two as he sank five straight birdies on the back nine to open up a three shot lead over John Senden (68) with defending champion Adam Scott (72), Thomas Bjorn (68), Jonas Blixt (71) and American youngster Jordan Spieth (70) finishing three under.

Although McIlory survived the cut which stood at four over, a number of established names missed out as their challenge ended before the weekend.

2013 Open champion Phil Mickelson was the biggest casualty after hitting a 73 at five over par. He was joined by USPGA champion Jason Dufner, Angel Cabrera, Graeme McDowell and Ernie Els. After finishing round one seven over par, Luke Donald's efforts to claw his way back into contention were also brought to an end.

Lee Westwood finished level for the tournament as he finished one under par, but was left to rue the same missed opportunities that tarnished his opening day.

I didn't play the par fives well enough again," Westwood said. "Over two days, I've made eight fives and that's where you make your scores. You need birdies over the weekend on them.

"There's good scores if you play well and disasters if you start hitting a few wild shots. I'm comfortable out there and can see a way around it."

Scotsman Stephen Gallacher and Wales' Jamie Donaldson both finished day two one under par to represent Britain's other hopes of catching leader Watson, with US Open champion Justin Rose and Ian Poulter both finishing two over after carding scores of 70.