Bubba Watson was set to take a three-stroke lead into the Masters weekend after a five-birdie run on the back nine in Friday's second round blasted him clear of the field.
Bubba Watson of the US reacts after making a birdie putt on the 14th green during the second round of the 78th Masters Golf Tournament at Augusta National Golf Club on April 11, 2014 in Augusta, Georgia
The 2012 winner started the day at Augusta National one off the lead, but a round of 68 left him three clear off the field at seven-under 137.
His closest challenger was Australian John Senden, who had a 68 to get to four-under 140.
A further stroke back came veteran Dane Thomas Bjorn on the back of a 68 and unheralded Swede Jonas Blixt, who carded a 71.
Freddie Couples, still competitive at 54, came next on two under after a battling 71.
Defending champion Adam Scott, who had a 69 on Thursday, fell back to level par after five holes, but back-to-back birdies at 12 and 13 pushed him back up the leaderboard.
Last man out Rory McIlroy endured a torrid day with double bogeys at the fourth and 10th pushing him out to three over.
Three-time winner Phil Mickelson was in a long wait to see if he would make it to the weekend, as he stood at five over after 36 holes with the cut projected at four over.