Mansfield have had an excellent start to the season, and managed to continue that thanks to a Walker-inspired come back in the game.
Thing started terribly for the seventh-placed side as they went behind in the first half courtesy of a Mel Benning own goal in the 36th minute.
However, the in-form side managed to turn it around in the second period thanks to two goals from their star man, Tyler Walker.
The first goal came thanks to a Mellis cross, which the forward was able to turn in from close rang, and the comeback was completed in the 82nd minute when Walker added a second thanks to a header from a great Hamilton cross to seal Grimsby's fate.