Robin van Persie guided Arsenal through to the next round of the Champions League on Wednesday, scoring his 20th and 21st goals of the season in a 2-1 win over Borussia Dortmund.
Dortmund dominated the opening exchanges and had Arsenal under pressure even after injuries to Sven Bender and Mario Goetze midway through the first half robbed the German champions of arguably their two key players.
But Van Persie headed in Alex Song's 49th-minute cross at the far post to put the home side ahead and secure progress from Group F with one match remaining.
The Netherlands striker tapped in with four minutes left before Shinji Kagawa got a goal back for Dortmund deep in injury time.
Van Persie now has four Champions League goals this season on top of 13 in the Premier League and four for his country.
''He's in a period where of course he doesn't have to look for goals,'' Arsenal manager Arsene Wenger said. ''They just come naturally for him. He's always in the right place at the right moment. It looks easy but it's not easy because he understands the game so well.
''He is completely focused on football. He thinks day and night about the game.''
But Van Persie had been mostly quiet Wednesday until Song drifted out to the left and suddenly darted between two defenders to cut inside and send over a cross. With Dortmund's defense exposed, Van Persie was unmarked and headed downward to beat diving goalkeeper Roman Weidenfeller.
Dortmund coach Jurgen Klopp gambled with his third substitute in the 64th, bringing on Lucas Barrios for captain Sebastian Kehl, but to no avail.
Dortmund never looked like equalizing and Vermaelen flicked on an 86th-minute corner kick to give Van Persie a simple close-range finish.
Kagawa salvaged some pride for Dortmund, which can still advance after Olympiakos beat Marseille 1-0 in the other Group F game, with a close-range shot of his own after a mix up between Song and Johan Djourou.
Arsenal has 11 points from five matches, four more than Marseille. Olympiakos is another point further back, with Dortmund on four.
But Dortmund will be without Bender for its final game against Marseille on Dec. 6. Klopp said the midfielder had broken his jaw and needs surgery in London before he could return to Germany.
Fresh from a Bundesliga victory at pacesetter Bayern Munich, Dortmund had attacked from the first minute and had three chances before Van Persie managed Arsenal's first on-target effort with an 11th-minute header that goalkeeper Weidenfeller easily caught.
Kagawa almost set up Robert Lewandowski for a shot before the Japan forward tested Arsenal keeper Wojciech Szczesny himself with a low effort. Dortmund then cut Arsenal apart with a swift counter that only broke down when Lewandowski inadvertently got in the way of Kagawa when he was trying to shoot.
But Dortmund was dealt a blow in the 25th when Bender had to be replaced. Bender fouled Vermaelen but the tumbling defender's trailing leg struck the midfielder in the face, sending him crashing to the ground in pain.
Bender was carried off and Goetze limped off just three minutes later with a knee problem, Klopp consoling the obviously distraught winger on the touchline.
In between those substitutions, Lewandowski sent a snap shot wide from 25 meters (yards) but Arsenal began to gain parity in the midfield exchanges despite Mikel Arteta's struggle to impose himself.
Marcel Schmelzer tested Szczesny again but Arsenal swiftly countered and only a full-stretch intervention of Theo Walcott's cross by Weidenfeller denied Van Persie a simple tap in.
With Moritz Leitner and Ivan Perisic on as substitutes, Dortmund also began the second half brightly with Szczesny saving from Kagawa but it was Van Persie that scored first.
''That hurt us, it really hurt us,'' Klopp said. ''They really gained confidence. We just played wildly and that's not us normally. Therefore we deserved the loss.''
