But Tiger Woods stole the show with a magical bunker shot for a birdie on the last to grab third place four shots back and put himself in with a great chance of ending a four-year Major drought.
While everyone else seemed stuck in reverse gear on a calm day at Royal Lytham & St Annes, 31-year-old American Snedeker registered a record-equalling 36-hole total of 130.
First round leader Adam Scott of Australia also played well as he came through with some late birdies to post a 67 after his opening 64 to take second place, one shot back on nine under par.
And Woods sits in third place on his own at six under par after holing his bunker shot for a second successive 67.
"My mantra all week has been to get the ball on the greens as fast as possible," Snedeker said.
"Once I'm on there I have a pretty good handle for the speed of the greens and I'm just going to try and keep doing that over the weekend."
Phil Mickelson slumped to a 78 for 151, missing the cut and continuing his poor Open record.
World number two Rory McIlroy also struggled, managing only two birdies in a 75 but he made the cut after finishing on 142, two over par.
Top-ranked Luke Donald (68) notched four birdies in a magical five-hole burst from the fourth as he remained on the fringes of contention on two-under 138.
Snedeker, who won the Farmers Insurance Open in California in January, reaped a rich harvest of birdies after ramming in a confidence-boosting 25-footer at the par-three first.
With most of his rivals toiling as light winds changed direction and organisers placed the flags in awkward spots on faster greens, Snedeker accelerated clear.
The blond American struck laser-guided approach shots at the sixth, seventh and ninth holes to set up three more birdie opportunities he gratefully devoured as he raced to the turn in 30 - four under par.
Snedeker, who has never won a major and missed the cut at the 2008, 2009 and 2011 Opens, made further inroads at the 11th and 12th before showing the touch of a master to get down in two from thick greenside rough at the 15th.
The American, who had a hole-in-one at the par-four 16th in practice on Wednesday, signed off with three more regulation figures to tie triple Open champion Nick Faldo's 36-hole aggregate of 130 at Muirfield in 1992.
"I've got a nice cushion now," said Snedeker. "I don't have to play the best golf over the next 36 holes.
"I have to play good golf but maybe not the best of anybody. The fans over here are great, very knowledgeable, and they applaud for great shots and it's good to realise that a 25‑footer sometimes is a great shot."
Donald, aiming to become the first Englishman to win the championship on home soil since Tony Jacklin in 1969, prompted trademark cries of 'Luuuke, Luuuke, Luuuke' with his birdie blitz.
The Englishman was forced to bring in Gareth Lord as a temporary bagman after giving regular caddie John McLaren a day off to attend the birth of his first child.
"The difference between yesterday's and today's round was I holed a few more putts," said Donald.
"The only disappointing thing was I gave myself a lot of opportunities from 100 to 150 yards with the greens being pretty soft and not much wind."
Mickelson, a four-times major champion, was at a loss to explain his performance.
"The last two months have been pretty poor play so I'm a little frustrated," he explained. "The scores are really far off. I don't know what to say."
Mickelson and defending champion Darren Clarke were among a host of high-profile players to miss the Open cut, made at three over par, on Friday.
Clarke shot a respectable one-over 71 to finish on seven-over 147 while Mickelson, a four-times major champion, slumped to a dismal 78 for 151 to continue his poor record in the tournament.
Six former Open champions from the United States failed to make the weekend -- Tom Lehman, Justin Leonard, Todd Hamilton, Ben Curtis, Stewart Cink and David Duval who won the last one held at Lytham in 2001.
They were joined on the way home by former world number one Martin Kaymer, double major winner Angel Cabrera, 1985 Open champion Sandy Lyle and United States Ryder Cup captain Davis Love III.
Former major champions Yang Yong-eun of South Korea, South Africans Charl Schwartzel and Trevor Immelman and American Lucas Glover also missed out.
World number three Lee Westwood flirted with danger before scraping through on three-over 143 with a level-par round of 70 to keep alive his faint hopes of a first major title.
Second-ranked Rory McIlroy and twice Open champion Padraig Harrington made it through on 142.
Britain's Richard Finch had the misfortune to take 10 at the par-four eighth on the way to a 79.
"I got into a bit of a pickle going up the eighth," he said after missing the cut. "It was a long 10 holes from there on in."
Earlier, a deluge of overnight rain took the Royal & Ancient organisers by surprise and left some areas of the course with standing water.
"We've had far more rain overnight than we were expecting unfortunately," said chief executive Peter Dawson. "There was 11 millimetres or so but the course can take it as the drainage here is good."