AFC Telford United are on course for just their fourth Conference Premier win of the season after moving into a 1-0 lead against Grimsby Town at half time.
Grimsby, who began the afternoon six points adrift of leaders Barnet, started well with Nathan Arnold having a stinging effort dealt with by Freddy Hall, before the Bermuda stopper denied Lenell John-Lewis after the striker had been played through on goal.
John-Lewis was proving to be a constant threat, with his next strike being blocked by Steve Akrigg, before Grimsby were denied again when Hall produced a fine save to deny Jon-Paul Pittman.
AFC Telford, who are 10 points from safety, had offered little in the final third but against the run of play, they took the lead on 34 minutes when Andy Parry drilled a long-range drive past James McKeown.
Grimsby ended the first half on top, with Arnold forcing Hall back into action, but the home side held on to take a narrow advantage into the break.
