A stubborn defensive display from Carlisle denied Rushden the chance to go top of the table in a 1-1 draw at Nene Park.
The home side almost took an early lead when Onandi Lowe saw a 35-yard free-kick come back off the underside of the crossbar.
Carlisle recovered and took a shock lead when Jon McCarthy played in Craig Farrell, who made no mistake from 12 yards after 12 minutes.
But promotion-chasing Rushden took just four minutes to equalise thanks to Lowe's eighth goal of the season.
Paul Hall lifted an inch-perfect cross into the penalty area and Lowe outjumped the defence to head home powerfully in the 16th minute.
Rushden lost the services of goalkeeper Adam Sollitt with quarter of an hour left when he was stretchered off after falling awkwardly. Injured replacement Billy Turley kept the visitors out.