Scott Dann had an early chance for the visitors but the centre-back failed to find the target with a free header following some poor marking from the hosts.
Rovers were punished for wasting that early opportunity when Novak latched onto a loose ball inside the penalty area to fire Huddersfield into the lead in the 15th minute.
Following the goal, it was Blackburn who enjoyed the majority of possession as they searched for a way back into the contest.
Danny Murphy stepped up from 12 yards for Rovers and converted the spot kick to complete the turnaround.
Danny Ward looked as though he would level the scores when he burst into the Blackburn area, but Olsson made a vital interception before the winger could pick his spot.
Novak ended a dramatic night by completing his brace with a close-range finish to claim a point for the hosts.