Bubba three clear at Masters
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 - by Timothy A. Clary
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.