North Ferriby United 1 (Stevens) Grimsby Town 1 (Hearn)
The Mariners started with a mixed side of youth and first teamers.
Simon Ford, who is set to sign for the Mariners on Thursday, lined up in the Town back four.
Liam Hearn made a welcome return alongside Anthony Elding in the Town attack, but the Town number 10 was substituted on 37 minutes after taking a kick on his Achilles.
Hearn had fired the vistors ahead on 26 minutes, a powerful strike from close in. But North Ferriby, who had dominated play, struck just before half time through Neil Stevens from 25 yards.
We later learned that Hearn is okay and was substituted as a precaution.
Town: Greg Fleming, Bradley Wood, Josh Morall, Jack Griffin, Simon Ford, Ben Cuff, Dayle Southwell, Andi Thanoj, Anthony Elding, Liam Hearn, Frankie Artus.
Subs: Lewis Smith, Harry Ashton, Will Peers, Robbie Bryant, Hamish Falconer, Blaize Kerr.