Besiktas suffered a 2-1 defeat against Borussia Dortmund at the Vodafone Park stadium in the Champions League Group C Match Day 1 clash on Wednesday.
Dortmund took an early lead on 20 minutes when Jude Bellingham found the back of the net and then Erling Haaland doubled the visitors lead before the half-time break.
Besiktas looked nervous in the first half and did not defend well.
Dortmund exploited the Black Eagles poor defensive display with clinical finishing wrapping the game up in the first 45 minutes.
The Black-Whites did perform better in the second half, dominating possession and creating several chances.
They were eventually rewarded for their efforts when Francisco Montero scored in the fourth minute of additional time but it ended up being nothing more than a consolation goal.
The defeat saw Besiktas end the first round of games in 3rd place, tied on zero points with Sporting Lisbon who are last on goal difference and suffering a 5-1 defeat against Ajax who went into first position.
Besiktas will take on Ajax next at the Johan Cruijff Amsterdam Arena on 28 September.