In the 22nd minute, Kalu directed a header past Regis Gurtner from Sergi Palencia's cross to give the hosts a lead.
But just when it looked like they had secured the maximum points, Eddy Gnahore levelled with three minutes from regular time to earn a share of spoils for Christophe Pélissier's men.
Kalu has now scored twice since joining Bordeaux in the summer, racking up 13 appearances.
Éric Bedouet's team finish 2018 placed 12th in the Ligue 1 log, garnering 22 points from 17 games. They start 2019 with a Coupe de France game against Le Havre on January 6.