Beaten only once now in 12 games, they are eyeing a play-off spot alongside a Rovers side, who looked distinctly second best on a windy night.
They made five changes after their FA Cup defeat by West Brom, while Northampton made three, the most significant being the loss of Adebayo Akinfenwa with a virus infection.
The much-travelled striker had scored six in four games since being borrowed from Millwall.
Without him the Cobblers looked short of power in front of goal, but still went close to taking the lead twice in the 20th minute.
First Ryan Gilligan fired in a close-effort which was hustled away with home keeper Steve Phillips in deep trouble.
Then the enterprising Ian Henderson hit a rising shot on the run against the bar.
Rovers were constantly fading in the final third and failed to worry Mark Bunn in the Northampton goal until the 45th minute when Chris Lines found Sean Rigg in front of goal.
Rigg won a tight scramble to poke in his first goal of the season and only the third of his young career.
Lines had arrived minutes earlier to replace David Pipe, who limped away with a thigh injury.
Northampton were stirred by the home goal and were rewarded with an equaliser within ten minutes of the restart.
Phillips was beaten by a ball across the face of his goal. It was headed out at the far post by Chris Carruthers but only as far as Poul Hubertz, who was left with a simple return.
Late on after Rovers centre-back Danny Coles had drawn a diving save from Bunn, Hubertz was within inches of winning it for the Cobblers with a header which had the keeper beaten.