Grimsby’s Conference title hopes were dealt a blow as Chester hit back late on to deny them a fifth straight win.
Ollie Palmer finished well from Jon-Paul Pittman’s cross on 21 minutes.
And, when Nathan Arnold’s effort hit the post, Pittman netted the rebound for a 2-0 lead on 67 minutes.
But Ben Heneghan smashed in a reply on 75 minutes before John Rooney’s penalty, after Gregor Robertson had fouled Matty Hughes, levelled it up for Steve Burr’s men six minutes from time.
Grimsby stay fourth, five points behind leaders Barnet, while Chester move back up into 10th spot, their highest league ranking since the club reformed in 2010.