Darryl Lee, manager of South Manchester 1st, described the 3-1 victory over title-chasing Mace as the best possible birthday present as he team took another step to ensuring top division football next season.
Two first half strikes from man-of-the-match David Chaytow gave South the upper hand in an Accountants League Premier Division clash.
Mace halved the deficit in the second half but three quick substitutions revitalised South who clinched the points when Chaytow's precision cross was headed home at the far post by Marc Yaffe.
There followed some ugly scenes as the Mace manager confronted the South keeper on the pitch.
Lee, who turned 50 this week, said: "We have a very young group with five or six teenagers playing every week and slowly they are coming to terms with the aggression of men's football.
"We are close to securing our place in the top division and are building a collective spirit and passing style of football that I am really proud of.
"There will be ups and downs to come but the win was probably my best present of the weekend."