The Shakers had been under a transfer embargo during a run of 12 games without a win, but with the ban now lifted, Blackwell has boosted his squad and his new-look side ended that run to move within a point of safety in League One.
Fit-again striker Andy Bishop broke the deadlock in the 25th minute before Nicky Ajose doubled the hosts' lead 10 minutes later.
And although the visitors piled on the pressure for the rest of the contest, Bury hung on to end Doncaster's 12-match unbeaten away run.
"I don't think anyone who's seen us play recently would begrudge us that," said Blackwell. "We've been playing well for a long, long time.
"It was a terrific 11-man display against a team that's second and were on a fantastic run. We had a few other chances to win it as well.
"The first goal was pure invention. The kids were bright, sharp, quick - and we felt that would be the undoing of Donny.
"It was pointless fighting them - we know how big and strong they are - and when we moved it quickly we caused them some real problems.
"Bishop gives us that bit more experience and we've missed that," added the Bury boss.
"His finish was first-class, he's worked his socks off this last six weeks to get fit and he ran himself into the ground."