Jason Day and fellow countryman Marc Leishman are halfway to delivering Australia a first green jacket.
Day posted 4-under-par 68 and leads the Masters Tournament by one shot over Leishman (73) and Fred Couples (71). The 25-year-old Day, who tied for second in the 2011 Masters, holds the lead for the first time in Augusta, at 6-under par.
Leishman, making his second Masters appearance, played solid while fellow first round, co-leader Sergio Garcia shot 76.
The 53-year-old Couples, the 1992 Masters champion, continued to turn back the clock in Augusta. One year after sharing the 36-hole lead with Jason Dufner, Couples birdied No. 18 to take the clubhouse lead at 5-under.
Angel Cabrera, the 2009 Masters champion, shot 69 and is tied for fourth with Jim Furyk (71) and Brandt Snedeker (70) at 4-under par.
Dustin Johnson led the tournament at 7-under through 13 holes until suffering a major implosion down the stretch. Johnson bogeyed No. 14, found the water at No. 15 for double bogey, added another bogey at the par-4 17th and closed with another double bogey for 71. He is five shots back at 1-under.
World No. 1 Tiger Woods posted 71 and is tied for seventh place with six others at 3-under. The four-time Masters champion made three birdies over a four-hole stretch on the front nine and was tied for the lead until an unfortunate break at No. 15. Woods watched his third shot hit the flagstick and roll back into the pond fronting the green. He recovered for bogey. At the closing hole, Woods three-putted for bogey to fall three shots off the pace.
World No. 2 Rory McIlroy eagled the par-5 eighth to turn around his day. He finished with 70 to move to 2-under.
Phil Mickelson posted 40 on the back side and limped home with 76, his worst round at the Masters in six years. The three-time green jacket winner stands at 3-over.
Defending Masters champion Bubba Watson recovered from a double bogey at No. 12 with four birdies over the next five holes. He failed to get up and down for par at the last, finishing with 73. Watson survived the cut on the number at 4-over.
Also advancing to the weekend is 14-year-old amateur Tianlang Guan, who received a slow-play penalty of one shot at No. 17. Guan is the lone amateur to survive the cut.