Phil Parkinson hailed Bolton's spirit after Callum Connolly's header gave them a first win in eight Sky Bet Championship games in a 1-0 victory at Birmingham.
The 21-year-old was shown a yellow card for only one of two late challenges in as many second-half minutes at St Andrew's before heading the only goal of the game moments later.
A dreary contest was short of both quality and chances but the visitors were deservedly rewarded for a gutsy and disciplined display.
Defeat to Lancashire rivals Preston at the weekend meant Parkinson's cash-strapped club came into the game having lost six of their last seven league outings.
"It was important to respond (to Saturday's result)," he said. "It was a spirited performance – every single one of them ran themselves into the ground.
"They didn't play for 45 minutes or 60 minutes, they stuck with it to the very end.
"Saturday was a disappointment but that was a full-on, committed, typical Bolton Wanderers display."
Lukas Jutkiewicz fired the first shot of note straight at Bolton goalkeeper Remi Matthews after 13 minutes and – seven minutes later – Blues defender Maikel Kieftenbeld blazed a 25-yard effort narrowly wide.
Bolton front two Donaldson and Josh Magennis made a nuisance of themselves from a long ball in the 36th minute and Craig Noone's shot from the edge of the box had to be smartly saved by Lee Camp, before the former Cardiff man curled a follow-up effort wide.
Che Adams found Jutkiewicz with a fine cross six minutes before the break, but his strike partner could only deflect the ball onto the roof of the net as he stretched to make contact.
The hosts might have gone ahead in first-half stoppage time, but Gary Gardner lacked composure when the ball fell to him on the edge of the area and his effort was well off target.
Birmingham should have gone ahead after 62 minutes when the lively Adams found Jota in space on the right of the penalty area, but Matthews brilliantly deflected his shot against the woodwork.
Referee Andy Davies decided against booking Connolly for a late challenge on Kerim Mrabti midway through the second half, but did reach for a yellow card two minutes later when the Everton loanee fouled Wes Harding.
Bolton made the breakthrough in the 71st minute when Donaldson – who was a nuisance against his former club throughout – won a free-kick on the right and Connolly headed Luke Murphy's delivery past Camp.
Asked whether Connolly was lucky to still be on the field, Parkinson added: "It would have been very harsh.
"I would have complained if he had been sent off for those challenges."
Adams missed a one-on-one opportunity to salvage a point in stoppage time as Matthews got down to keep out his low effort.
Birmingham boss Garry Monk said: "We have to be frustrated and disappointed – our performance with the ball was below where it should have been.
"Che's been tucking them away for fun but you look back and the keeper has dived early, and luckily for him gone the right way.
"Nine times out of 10 that ends up in the back of the net.
"We fought to the end but you have to make the most of those few chances when Bolton come and play the way they did."