Niclas Fullkrug scored twice as Werder secured a 3-2 away win against Mainz, before becoming involved in a heated exchange with home midfielder Nadiem Amiri after the final whistle.
The confrontation was verbal, with Werder midfielder Juri Reger stepping in to separate the pair.
Fullkrug’s goals took his league tally to eight, making him the competition’s leading scorer.
Werder are sixth in the table with 12 points following their victory.