DORTMUND, Germany (Kyodo) -- Japan forward Daizen Maeda scored an early equalizer, but his Scottish club Celtic suffered a 7-1 loss away to Germany's Borussia Dortmund in their second league-phase match of the Champions League on Tuesday.

Maeda canceled out Emre Can's opener with his goal in the ninth minute, bundling home Arne Engels' cross at BVB Stadion in Dortmund. Karim Adeyemi then helped Dortmund open up a 5-1 halftime lead by completing a hat-trick in a span of 30 minutes.

"It showed where we actually stand. We still have six games left, so we'll switch our attention," said Maeda, whose loose touch outside his own box led to Adeyemi's third goal.

"There are situations in Scotland where losing the ball doesn't end up conceding a goal, but they take that one chance on stages like this. That was my mistake."

Maeda's Japanese teammates Kyogo Furuhashi and Reo Hatate also played against the German side.

In Celtic's 5-1 opening victory over Slovakia's Slovan Bratislava on Sept. 18, Maeda scored his first-ever Champions League goal as he entered his third season in Europe's premier club competition.