The Mariners boss had to watch in dismay as his side slumped to their fifth successive defeat and down into a relegation dogfight.
Walsall, meanwhile, increased their lead at the top of League Two to six points with a game in hand as they continue to steam towards their goal of promotion.
The latest home success was something of a milestone for their matchwinner Martin Butler who notched his first goals in 18 games.
He proved his first-half strike was no fluke as he added his second goal in the 78th minute to seal Walsall's latest success.
Other notable contributions came from Scott Dann, skipper Michael Dobson and Craig Pead but the surprising feature was Walsall's failure to really dominate a struggling Grimsby side, who have failed to score a single goal in their recent five-game slump.
Walsall attempted to overpower Town and it appeared as if the league leaders would swamp the opposition when a back-header from Dann in the opening couple of minutes was bravely saved by Phil Barnes.
The Saddlers' front men have not been very consistent and it took a lot of hard work before they managed to break Grimsby's resistance in the 27th minute.
It was a mistake by Simon Grand which allowed Hector Sam to provide a right-wing cross for his fellow striker Butler to end his recent goal drought with a well directed header out of the reach of Barnes.
Any hopes of the Saddlers capitalising upon this advantage failed to materialise for the rest of the first half.
Grimsby occasionally made a break down the right, but their only real goal attempt was a close-range header from Grand.
Ciaran Toner also went close early in the second half when Walsall made hard work of dispatching Grimsby.
Chris Westwood, Dean Keates and Dann all had reasonable opportunities to excel in front of the television cameras but their efforts were off target.
But Butler finally snapped up the second vital goal in the 78th minute.
Newcomer Par Cederqvist could only get a slight touch to Mark Wright's cross, but Butler was on hand to apply the finishing touch.