Dortmund's "Borussia" strategist Jurgen Klopp was forced to take off his cap in front of Arsenal's manager Arsene Wenger.
On Wednesday, the German team lost 0-1 at home in the Champions League match of Group F and complicated their chances of advancing.
According to J. Klopp, in the spring "Arsenal" could even win the tournament.
"They can win, especially if they don't face Bayern Munich. Arsenal is represented by young, healthy footballers who played very smartly today," said the German.
"Our group is very strong, and it's good that we still have chances to go further - we will have to win the remaining two matches.
Today we created plenty of opportunities to score, but the English took advantage of the first chance and my players failed to retaliate.