The first half saw top drawer saves from Adrian Littlejohn and Marc Bridge-Wilkinson before his defence badly let him down in a three minute spell in the second half.
Davison's second competitive home debut came four and a half years since the 1-0 victory over Port Vale in March 1999, Davison's last game before leaving for Sheffield United.
Vale boss Brian Horton was quick to praise Davison for his heroics.
"I thought we played better in the first half than we did in the second to be honest," Horton told the Grimsby Telegraph. I was really happy in the first half. Their keeper kept them in the game with two magnificent saves.
"We caused them all sorts of problems in the first half, but their keeper was man of the match; he was unbelievable.