Aalborg have now recorded three wins and a draw from four Champions League matches and is guaranteed to finish in either first or second place in their group, where Paris Saint-Germain is also in contention for the top spot.
Wednesday's match in Northern Jutland began as an evenly matched affair, but roughly midway through the first half, Aalborg tightened up their defense while maintaining the high-octane pace that had characterized the opening stages.
Juri Knorr, in particular, was in dazzling form, scoring several goals during the "second wave" of the fast-break phase. Displaying great vision, he would briefly take the pace out of the rapid attack, spot a gap, and strike.
This left Zagreb trailing by four goals at halftime.
The Croatian visitors gradually settled into their stride again in the second half, though the play was far from elegant. Zagreb was clearly the inferior handball team on the court, focusing their energy on disrupting Aalborg's game as much as possible.
At one point, the play became so rough that Jovica Nikolic was shown a red card for kicking Juri Knorr between the legs.
Coach Simon Dahl called a timeout, urging his players not to get drawn into the dirty tactics. Instead, he wanted the team to play patiently and seal the victory. However, things didn't quite go to plan.
Aalborg allowed Zagreb back into the match but ultimately managed to close it out in their favor.