When Woods, chasing a 15th major title, first suggested in a post-round interview he had not dropped the ball in the right place, Augusta rules chiefs reviewed the incident.
They then changed their minds, handing him a two-shot penalty, but invoked a recent ruling to waive the disqualification that used to follow the signing of an incorrect scorecard.
"I'm right there in the ball game," said Woods, who has never won a major when trailing going into the final day. "As of right now I'm four back with a great shot to win this championship."
Masters third-round stats
Co-leader Angel Cabrera, the 2009 champion, is the world number 269
Cabrera has won no tournaments on major tours since his 2009 Masters
Rory McIlroy took a triple-bogey seven on the 11th and double-bogey seven on the 15th in his round of 79
Adam Scott had a four-shot lead with four to play in the final round of the Open last year. The Australian goes into the final round at Augusta one off the lead
There is only one major winner (Cabrera) above Tiger Woods on the leaderboard
Thorbjorn Olesen leads the average driving distance standings with 300.33 yards, ahead of Scott Piercy and Phil Mickelson
the world number two, slumped to a seven-over 79, coming home in 42, to finish five over.
was the leading Briton after a 73 left him in a group on two under, while South African Tim Clark (67) finished alongside Woods at three under.
"It's a 73 that could have been a 70, but I still feel like I'm going to have a chance," said Westwood, who is still seeking a maiden major at the 60th attempt. The 39-year-old was second at Augusta in 2010 and third in 2012.
Nick Faldo was the last Briton to win at Augusta when he overcame a six-shot final-round deficit on Greg Norman in 1996.
Snedeker, who spent five weeks out with a rib injury earlier in the season, shot 12 pars in a row before picking up shots at 13, 15 and 16.
The 32-year-old, who
scooped the $10m FedEx Cup
last season, played in the final group in 2008 but took a closing 77 to finish tied third behind Trevor Immelman.
Snedeker also finished third in last year's Open after leading at the halfway point with the tournament's joint-lowest 36-hole total.
"I've spent 32 years of my life getting ready for tomorrow and I am 100% sure that I'm ready to handle it, no matter what happens," said Snedeker. "I'm going to be disappointed if I don't win, period."
Cabrera shows his Masters class
the 2009 Masters champion
, birdied the 16th and 18th to grab a share of the lead. The 43-year-old, who won the US Open in 2007, finished seventh at Augusta in 2011.
"In 2009, I was nervous, anxious," said Cabrera. "But now I'm very comfortable. I know what I've got to do to be able to get the win."
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