Augusta, GA (SportsNetwork.com) - Bubba Watson poured in five straight birdies on the back nine Friday to soar three shots clear of the field at the Masters.
That birdie string moved Watson to minus-8, but he bogeyed the last for a 4- under 68, which left him at 7-under-par 137 after 36 holes.
Watson, the 2012 champion, walked off the course three strokes clear of first- round leader Bill Haas, who was even-par after seven holes of his second round.
Thomas Bjorn matched Watson's 68 to move into third place at 3-under 141. Bjorn's best finish at the Masters was a tie for 18th in 2002. Fred Couples (10 holes) and Jimmy Walker (9 holes) were still on the course at minus-3.
Jonas Blixt, John Senden and 2003 champion Mike Weir were 2-under par and also still on the course.
Kevin Streelman (71) and Stephen Gallacher (72) were tied at 1-under-par 143. Russell Henley, Kevin Stadler, Rickie Fowler and K.J. Choi were all minus-1, but still playing their second rounds.
Defending champion Adam Scott was 3-over par through six holes, which dropped him to even-par for the tournament.
Watson, who won the Northern Trust earlier this year, started round two with six straight pars. He birdied the par-4 seventh, but gave that shot back on the ninth. He failed to get up and down for par from over the green.
The 35-year-old made the turn at 3-under, and remained there as he parred the first two holes of the second nine. He flew into the lead from there.
Watson stuffed his tee shot inside four feet at the 12th and converted that for birdie. He 2-putted for birdie on the par-5 13th to take the lead at minus-5.
He was the first to reach 5-under par for the tournament. At the 14th, Watson poured on a long, right-to-left breaking putt to make it three in a row.
Watson chipped to six feet at the 15th and rolled that in. His final birdie in run came at 16, where his tee shot stopped inside four feet. He parred the 17th, but dropped a shot at the last.
Watson missed the green left with his approach. He chipped inside five feet, but pulled the putt to the right. He tapped in for a closing bogey.
"I made a solid par on 11, hit a great iron shot into 12 and made a birdie somehow there. Thirteen is gettable with the wind, I got lucky on 14 again because I saw Sergio's chip, so I got to follow that, and then a great iron shot at 16," Watson explained.
Lucas Glover (69), Matt Kuchar (71), Louis Oosthuizen (75) and Gonzalo Fernandez-Castano (69) are all finished at even-par 144, while Henrik Stenson (72) is one back at plus-1.
The cut line of top 50 and ties, or anyone within 10 shots of the lead, currently stands at 4-over-par 148. If that number moves to plus-5, three-time winner Phil Mickelson, Ryan Moore, Sergio Garcia and Luke Donald would be among those to make the cut on the number.
Dustin Johnson (plus-7), 2008 Masters champion Trevor Immelman (plus-9) and 2011 PGA Championship winner Keegan Bradley (plus-9) are among those finished two rounds outside the cut line.