Justin Rose maintained his two-stroke lead at the Masters with a nerveless one-under-par 71 on Friday.
-6 Justin Rose (Eng)
-4 Jose Maria Olazabal (Sp), Alex Cejka (Ger)
-3 KJ Choi (Kor), Phil Mickelson (US)
-2 Ernie Els (SA), Charles Howell III (US), Davis Love III (US), Chris DiMarco (US), Fred Couples (US)
The 23-year-old Englishman, who carded a 67 on Thursday, got up and down from a greenside bunker at the last to preserve his six-under-par total.
With six holes to play, Rose had been tied at six under with playing partner Chris DiMarco, but the American dropped four shots down the stretch.
Alex Cejka and Jose Maria Olazabal lead the chasing pack at four under.
Rose played steady golf on the front nine, picking up a birdie on the fifth, to reach the turn at one under for his round, six under for the tournament.
But his second bogey in two days at the par-four 11th dropped him to five under, a shot behind DiMarco.
The Hampshire-based youngster hit straight back, though, with a glorious iron to within 18 inches of the cup at the short 12th.
Level once more, DiMarco was the first to crack when he put his second into Rae's Creek at 13 and ran up a double-bogey seven - his first dropped shots of the tournament.
DiMarco then bogeyed 14 and 16 while Rose parred all the way home to seal a four-stroke swing in six holes.
Korea's KJ Choi was another who threatened Rose's lead when he stormed to the turn in 30 shots. His six-under-par score matched Johnny Miller and Greg Norman's record for the front nine at Augusta.
But like DiMarco, Choi stumbled on the back nine to fall back to three under, one behind a resurgent Olazabal and unheralded Cejka.
Choi's 36-hole total of 141 was later matched by Phil Mickelson, who carded an impressive 69.
Ernie Els, Charles Howell III, Davis Love III, DiMarco and the evergreen Fred Couples are all in contention at two under.
But everybody at Augusta this weekend will be wary of a certain Tiger Woods.
Completely out of it at four over after the 14 holes he managed on Thursday, the world number one methodically climbed back into the tournament on Friday.
And at level par after 36 holes, nobody will be surprised if Woods starts a serious challenge for his fourth Masters title on Saturday.
Defending champion Mike Weir, however, will play no part in the next two days until he is called upon to present the new champion with his Green Jacket.
The 33-year-old Canadian was one of a number of big names that failed to make the four-over-par cut.
"My all-round game hasn't been sharp but today it was a lot better," he said. "I was just trying to fight back but it was a tough golf course today to do that."
Others to make an early exit included the crowd favourite John Daly and the highly-rated Australian Adam Scott.
But two of the five amateurs did make it past Friday.
Casey Wittenberg, the US Amateur runner-up, and Brandt Snedeker, the US Amateur Public Links champion, both made the mark on the number.