Ahlenfelder refereed 106 games in the Bundesliga as well as 77 2. Bundesliga games.
Ahlenfelder is best remembered for the game between SV Werder Bremen and Hannover 96 in the 1975–76 Bundesliga season when he called half-time after 32 minutes instead of the regulation 45. After complaints by the players Ahlenfelder questioned his assistant who confirmed that it was indeed too early to call half time. He continued the first half but still stopped it a minute early. Later questioning revealed that Ahlenfelder had been drinking during his lunch before the game and felt a little confused. He received a short ban from officiating Bundesliga games but was soon allowed back as a referee.
In the 1983–84 Ahlenfelder was voted best German football referee and awarded the Golden Whistle. (Source : Wikipedia)