(CNN) -- Bubba Watson will take a three-shot lead heading into the final two rounds of the Masters at Augusta National after firing a four-under par 68 on Friday.
An incredible run of five straight birdies on Augusta's famously difficult back nine helped put the 2012 champion in pole position heading into the weekend.
Watson's initial progress was unremarkable as he reached the turn in even par -- a birdie at the par-four seventh was canceled out two holes later with bogey at nine.
But his challenge burst into life at the par-three 12th when he fired his tee shot to two-and-a-half feet to leave a simple tap in for birdie.
Another followed at the 13th hole before an astonishing putt at the 14th made it three in a row.
Two further birdies saw Watson reach eight-under before his hot streak ended with a par at the 17th followed by a bogey at the last.
Together with his opening round 69, Watson is now seven-under par and in control of the tournament.
"It's never easy," Watson said. "It's a great test of golf and I just got some good breaks, some good things that went my way. Guessed the wind right on the stretch of holes on the back nine there."
Watson's string of birdies bettered a run of four he made in the final round when he won two years ago.
"That five hole stretch was good. It's one of those where you're not focused on what you're doing, you don't know that you're making all these birdies, you're focused on one shot at a time," he said.
Watson was one of the early finishers on day two and no one came close to challenging him as the afternoon wore on.
Overnight leader Bill Haas stuttered to the turn in one over, before watching the wheels come off his round at Amen Corner completing the three-hole stretch of 11, 12 and 13 in four-over par.
The 31-year-old ended the day with a 78 to fall back to two over par.
He wasn't the only one to struggle as the wind picked up and the greens dried out.
Defending champion Adam Scott toiled on the opening nine dropping three shots before mounting a recovery with birdies at the 12th, 13th and 15th to finish at three under after 36 holes.
"It was so difficult early on, the greens were very dried out and it was hard to make some putts -- it was hard to hit them confidently," Scott said.
"I didn't really play well at the start but then made the turn -- you can make it happen if you get through the first couple of holes on the back nine."
The Australian finds himself in a four-way tie for third alongside Dane Thomas Bjorn (68) and Master's rookies Jonas Blixt from Sweden who posted a 71 on Friday and 20-year-old Jordan Spieth from the U.S. who shot a round of 70.
Watson's nearest chaser is another Aussie, John Senden, who finished on four-under par after shooting 68 on Friday.
Fred Couples, the 1992 champion, is also in the mix after a second consecutive round of 71 left him two-under par and in a tie for seventh with compatriots Jimmy Walker and Jim Furyk.
America's Kevin Streelman, Russell Henley and Kevin Stadler are joined at one-under par by Welshman Jamie Donaldson and Scot Stephen Gallacher.
Further down the leaderboard, it was a good day for three ex-champions from the 1980s.
The 1985 winner Bernhard Langer and Larry Mize, whose sensational chip-in at the second play-off hole won the 1987 Masters, both finished comfortably inside the cut at two-over par.
Scot Sandy Lyle, who triumphed in 1988, also squeezed in at four-over par -- the same score as Northern Ireland's Rory McIlroy who limped to a 77.
Plenty of big names, however, will not be coming back at the weekend including three-time champion Phil Mickelson who ended five-over on Friday following a round of 73.
Luke Donald also missed the cut by one stroke as did Spain's Sergio Garcia, South Africa's 2011 champion Charl Schwartzel and 19-year-old English amateur Matthew Fitzpatrick.