Arsenal is on track for the knockout stages of football's Champions League after beating Greek side Olympiakos 3-1 in London.
The Gunners went ahead through Ivory Coast international Gervinho before half-time at the Emirates Stadium, but Olympiakos quickly equalised inside three minutes.
English champions Manchester City needed a late Mario Balotelli penalty to save their campaign against German visitors Dortmund, after falling behind after half-time in a lacklustre effort.
The 1-1 draw continues City's indifferent start to the season.
German recruit Lukas Podolski scored in the 56th minute then Welsh youngster Aaron Ramsey sealed the win in the 94th minute.
Elsewhere, the nine-time European champions Real Madrid thrashed Ajax 4-1 in Holland with Cristiano Ronaldo scoring a hat-trick, while the seven-times winners AC Milan needed a late own goal to beat Zenit St Petersburg 3-2 in Russia.