Flensburg led 18–14 at halftime, but Kiel fought back and first opened a four-goal lead at 17–13 a minute before the break. Slovenian playmaker Domen Makuc became central to the hosts’ attack after the interval.
Flensburg recovered despite trailing by as many as five goals. A three-goal run brought the visitors to 28–30 in the 55th minute, and Marko Grgic equalised in the final minute after a Kiel turnover.
Köster appeared to score with the last play, but the goal was ruled out after several minutes of video review. Both clubs remain unbeaten on 11 points with identical 11:1 records; Flensburg stays top on goal difference. Makuc scored nine for Kiel, while Aymeric Minne and Simon Pytlick scored seven each for Flensburg.