The hosts ran in nine tries to two in a one-sided cross-Jukskei derby, bouncing back strongly from their previous week's defeat to Munster in Ireland.
Returning Springboks played a major role, with eighthman Cameron Hanekom earning man-of-the-match honours after scoring two tries in a powerful display.
"I'm just proud of the guys. We knew we had to be at our best to beat a side that's in form," Ackermann said.
"The focus was on making sure we start well, and we have our set piece sorted out.
"Credit to the players, the mental strength and maturity they showed out there to start well and stay in the fight even though things didn't go our way.
"We lost a few balls where we had opportunities, but we just stayed on the task."
Ackermann was particularly impressed by how quickly the returning Springboks adapted to the team's systems after limited preparation time.
"I'm very pleased. It shows the character and the quality of the players to buy into what we want to do," he said.
"The coaches put a lot of effort into sending them stuff on Monday, and then on Tuesday they had meetings with them separately to bring them up to speed.
"They learned everything quickly, and on Wednesday we had a day off, and on Thursday we trained.
"It wasn't perfect; there were mistakes, but you could see that they were buying into what we wanted to do, and quickly settled in.
"I think there are so many tries where there were players involved that created something, and then the Boks showed their class as well.
"It's good that those guys contributed, but what pleased me as well was the bench. The guys came on and made a difference, and kept the pressure on the Lions."
On Hanekom's standout performance, Ackermann stressed the team effort behind the opportunities.
"Every player has got his strengths, and Cameron has shown his strengths that stood out in some of the phases today," he said.
"But again, you must look at how the opportunities were created; there are a lot of players involved in that.
"He hasn't played with us for a long time, and he came in and slotted in nicely. I'm just proud of his effort; he's a quality player."
Looking back on the early stages of the match, the coach admitted there were plenty of nerves at the start before the Bulls found their rhythm.
"The first 10 to 15 minutes were a bit nervy. I think the boys found their feet, and after we found our feet, we had a few opportunities even in the first half which we didn't capitalise on," he said.
"As soon as we got our opportunities again, we took them better; that was the main work on for us from the Munster game. We knew this wasn't going to be an easy game."
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