The 1-0 victory, thanks to a stunning Dan Cotton strike, was in no way an accurate reflection of a game which Stamford dominated, largely thanks to the excellence of winger Tyrone Kirk.
Keast was delighted with the win and equally pleased with the clean sheet having watched his side ship four and come from behind three times before eventually beating Lincoln United 6-4 in extra time in the Unibond Challenge Cup last Saturday.
He said: "We deserved to beat Spalding and by more than the odd goal. We worked hard, created chances and defended excellently to ensure they created very little.
"Tyrone was given the licence to roam and that worked perfectly and Dan's strike was absolutely superb.
"It was a good performance but we've got to build on it now and go on a run."
While the fans will remember Saturday's clash with Lincoln as a thriller, Keast has already put it out of his mind.
"I was relieved to get through," he admitted.
"Scoring six is fantastic but conceding four in the manner we did is not acceptable.
"The lads showed good spirit to come back but some of our defending was shocking.
"I think a few people looked at the score and assumed I wasn't taking the competition seriously. I don't have a big enough squad not to take any competition seriously and I'm certainly not a believer that you can ask your side to turn it on in one game but not in another.
"If we're to go on a good run and pick up results then that includes the cups as wins are what we need to boost us."
The Daniels face lowly Willenhall in a league clash at the Vic Couzens tomorrow before visiting struggling Grantham for a President's Cup clash on Tuesday.
Keast added: "The most important thing is to maintain the levels we showed against Spalding.
"Three points is the priority to give ourselves further encouragement but we must not let the mistakes of last weekend return."
Stamford will be without Ryan Collis, who was carried off with an ankle injury at Spalding, while Scott Taylor's hamstring injury will keep him out for at least another fortnight.
Danny Steadman is struggling to recover from illness while Adam Cunnington is a doubt with an ankle injury.