"We certainly weren't satisfied with how we played but, yeah, the result was pretty good," Mzungu said at his team's recovery session on Sunday.
Coach Ross Lyon was stern with his team at half-time for a lack of pressure around the Lions' ball carriers.
"It's something we pride ourselves on, putting pressure on and laying tackles and we were well down," Mzungu said.
"That was due to our intensity. It wasn't good enough early, and to Brisbane's credit they really came out and put up a fight and pressured us."
The Dockers players took five days off to freshen up during the bye week but Mzungu refused to blame that for his side's sluggishness in the opening half.
"I wouldn't put it down to the bye. It's just a little disappointing we didn't spread as well as we could've out of stoppages," he said.
"I think as the game wore on we were a little bit better and we made them defend a little bit better."
The Dockers still only conceded six goals with their defence again standing firm.
It was the eighth time under Ross Lyon the Dockers had kept an opposition side to 48 points or less.
In the previous 380 games prior to Lyon's arrival, Fremantle had managed that feat just three times.
"We don't try and get into shootout footy. It's not our style, it's not how we want to play. We defend as well as we can," Mzungu said.
"We love turning the ball over. We'd like to score a bit more but the way we held them to six goals was really pleasing.
"But if we can work a little bit more on our ball use, it would help going forward."
Mzungu said sharper ball use would be the focus of the week as the Dockers prepare to host North Melbourne next Sunday.
The Kangaroos were a far better side than their 4-7 record suggested, he added.
"They've put some really good results up. They've been really close," Mzungu said.
"Their win-loss count could be the other way around quite easily so we don't want to take them for granted or take them lightly, that's for sure, so we know what's coming over."
The Dockers are on a seven-match unbeaten run and Mzungu credits the team's "elite" preparation as the reason for their outstanding form.
"We just prepare really well," Mzungu said.
"Every moment we're at the club we're preparing to play our next game and our next training session.
"It's pretty simple. We're an elite group in how we get ourselves right for games so I think that's the key," he said.
