Torquay led through Ryan Jarvis' 62nd-minute strike but the Cobblers hit back at the death to earn a share of the spoils.
Jarvis needed just one touch to clinically finish Torquay's best move of the match.
Nathan Craig made a brilliant crossfield pass to Danny Stevens, whose cut-back from the byline was finished first-time by Jarvis.
On-loan Reading central defender Angus MacDonald made a brilliant clearance off the line midway through the first half to head Chris Hackett's cross-cum-shot out from under the crossbar.
Town ended the first half with Hackett and Ben Harding both testing home goalkeeper Michael Poke.
Langmead had a brilliant chance to level in the 80th minute as Torquay failed to clear a corner but the Town skipper fired wide from close range.
However, he made no mistake when the ball fell to him six yards out in stoppage time.