Blues halted a run of nine consecutive games without a win with a slender 1-0 win against The Bees at St Andrews on Saturday courtesy of a 40th minute own goal from James Tarkowski after which the Blues boss described Donaldson's performance against his former club as 'brilliant'.
"Clayton Donaldson was brilliant against his old team," Rowett said after the game.
"He has been monumental this season and when we play that lone striking role he plays it as well as anyone. He physically imposes himself on the game and is such a great worker for the team.
"That unselfishness gets him into positions as he displayed with the own goal that won the match.
"This is the biggest win of our season. It was an absolute crucial win. To get it against a Brentford side who are going really well under manager Mark Warburton was very important.
"I thought we had to get back to basics after a couple of heavy defeats.
"Perhaps we have been too open in games and too attacking to please people.
"I thought we defended brilliantly against Brentford and I thought that with a little more composure and a little more quality and a tab more ruthless play we could have added to the single goal."