The visitors quickly saw their early momentum dealt a huge blow after Jordan Torunarigha was sent off in the seventh minute - two minutes after Davie Selke's early opener.
Unfazed by the numerical disadvantage, Kalou would, however, double their lead in the 31st minute benefitting from a Valentino Lazaro assist to grab his seventh league goal in 14 appearances this term. The 32-year-old had netted twice in their 3-1 win over Hannover 96 on Wednesday.
Selke completed his brace after the break and the Bulls forced a comeback, but failed.
Will Orban scored in the 68th minute before Marcel Halstenberg netted in injury time but the game would end in a 3-2 victory for the visitors.
The Cote d'Ivoire international played for 72 minutes while Naby Keita could not help his side to a positive result and now, they are yet to pick maximum points in their last four league ties. The Liverpool-bound Guinea midfielder was booked on the stroke of halftime.
Both sides will resume league duties next year as Leipzig finished 2017 in fifth position while Hertha climbed to 10th in the German top-flight log.