With less than five minutes to play, key forwards Ty Vickery and then Jack Riewoldt sealed the result with back-to-back goals, giving the Tigers one of their best wins under coach Damien Hardwick.
Labelled a week-to-week proposition by Hardwick as he battles a calf problem, Deledio underlined how valuable he is to the Tigers with two clutch goals in the fourth quarter.
He finished with 30 possessions (10 contested) and 13 marks, spending significant time deep in the forward line.
He was only shaded by Cotchin, who willed the Tigers over the line in a captain's performance, finishing with 32 possessions (18 contested) six clearances and two goals.
There were moments when Collingwood looked set to break the match open and cruise to their fifth win for the season, but every time Richmond responded.
The win ended a three-game losing streak for the Tigers and ensured their season remained alive after a 2-4 start to the year that heaped pressure on Hardwick.
Defender Alex Rance also stood tall in a number of roles, starting on-ball but finishing on Cloke when the Magpies' spearhead got himself rolling.
Making the win more significant was the fact the Tigers did it without their best player this season, Shane Edwards, who was a late withdrawal.
They also got over the line while blooding debutants Connor Menadue and Liam McBean.
Cloke started opposed to second-gamer Todd Elton and by the first break he had taken six marks and kicked one goal as the Magpies built a 20-point lead.
The Tigers needed their leaders to respond and that's exactly what happened in the second term, with Cotchin and Maric getting on top in the middle and each pushing forward to kick goals.
Rance won a number of crucial contests as a loose man and after the Tigers kicked five goals in nine minutes in the second quarter the Tigers had a 10-point lead.
The Magpies' loss was soured by what appeared to be a minor knee injury for defender Alan Toovey