We've won four games on the trot since surrendering a 3-0 half-time lead against the champions in September.
"Sometimes you need a result like that," said Dean after Saturday's win against Middlesbrough.
"Last season at Southampton we lost 4-3 at Tranmere and after that we went eight games unbeaten and kept seven clean sheets. Sometimes things like that give you a kick up the backside and get you going again."
'Deano' also believes he's starting to settle into his new surroundings - that United game was, after all, his debut.
"I feel over the last couple of games especially, forgetting the Manchester United game, things have gone well," he said.
"Derby was quite comfortable and we played well but the last two games we've had to defend and that's when I'm at my best, when I've had to defend."
Alen Boksic certainly put Dean's defensive qualities to the test at the Lane on Saturday.
Dean added: "He's a first class player and a player I rate very highly.
"He's so sharp and bright and always a handful. You have to be switched on for 90 minutes against him - he had one chance against us and that's all he needed.
"There will be games like this though when teams try and frustrate us and we'll have to grind it out and break them down. We did just that."
Dean Richards has reiterated Glenn Hoddle's belief that the shock of our 5-3 defeat against Manchester United has worked as a stepping stone to our recent run of form.