Canada's Mike Weir has opened up a commanding lead at the US Masters after carding a second-round 68.
Left-handed Weir moved to six under and holds a four-shot lead going into the third round.
Darren Clarke leads the chasing pack on two under, with Phil Mickelson and amateur Ricky Barnes a further shot adrift.
Tiger Woods only ensured his continued participation at Augusta with a pressure putt for par on the last, when a bogey would have seen him miss the cut.
The defending champion, looking for a third successive green jacket, had looked to be clawing his way back up the leaderboard on Friday after a poor opening round.
However, he again struggled when play got underway at 0820 local time despite the clear blue skies and perfect conditions for golf.
A double-bogey five on the fourth hole, and a bogey on the fifth, saw Woods flirting with a missed cut for the first time in 101 tournaments.
England's Justin Rose was another who just made the cut at five over.
-6 Mike Weir (70, 68)
-2 Darren Clarke (66,76)
-1 Phil Mickelson (73,70) & Ricky Barnes (69, 74)
Level Brad Faxon (73, 71), Vijay Singh (73, 71), David Toms (71, 73), Jose Maria Olazabal (73, 71) & Paul Lawrie (72, 72)
But a host of big names will be heading home early, most notably Padraig Harrington, David Duval, Colin Montgomerie and Bernhard Langer, the first cut he has missed at Augusta since 1983.
The second round resumed on Saturday morning with Weir two shots ahead of Clarke, the leading European contender.
However, a double bogey at the 11th gave the Ulsterman a terrible start and Weir a commanding lead which he never surrendered.
At one stage Mickelson closed to within two, but, after three birdies, a double bogey set the American back on his heels.
Ernie Els, who like Woods was out of sorts on the opening day, shot back into contention with a dazzling display.
The South African put memories of his first round 79 behind him with a wonderful 66, which was enough to see him join a log-jam of 12 players at one over.
Former Open champion Paul Lawrie is well placed at level par in a quintet which includes two past Masters winners, Vijay Singh and Jose Maria Olazabal.
Former USPGA holder David Toms and Brad Faxon, the early clubhouse leader, complete the group.
However, as with any player from Clarke down, they will have to make some low scores if they are to bridge the gap to the runaway leader, let alone challenge him.