A hard-fought clash, watched by 5,828 at Sixfields, came alive in the final twenty minutes as John Marquis put Town in front only for James Spencer to level for the U's.
With defeats for Oxford United and Plymouth Argyle, however, Northampton's lead at the top of League Two has actually been stretched to fourteen points with only ten games to play.
Cambridge boss Shaun Derry was pleased with his side's resilience against the league leaders, telling his club's official website that the U's 'thoroughly deserved a point' from the game.
Northampton go to Stevenage this coming weekend before an Easter double-header which could see the promotion champagne prepared and ready for what now looks to be an inevitable celebration.