London: Yaya Sanogo ended his 15-month wait to score for Arsenal on Wednesday by helping the London club beat Borussia Dortmund 2-0 and qualify for the Champions League knockout phase for the 15th successive season.
However, victory came at a cost to a side that has struggled recently in the Premier League. Captain Mikel Arteta was forced off with a calf problem that manager Arsene Wenger said "looks quite serious." Midfielder Jack Wilshere was already sidelined and will discover on Thursday if his requires ankle surgery.
Sanogo, who scored in the second minute, limped off late in the game.
By that point, though, a place in the round of 16 already seemed secure after Alexis Sanchez scored early in the second half as Arsenal halted a three-game winless run in all competitions.
With a game to go in Group D, Dortmund and Arsenal have secured the two qualification places with only top place to play for next month.
"I'm very proud of (qualifying for a 15th consecutive season) and the club deserves a lot of credit for that," said Wenger, whose best Champions League finish with Arsenal is as runner-up in 2006. "It's not enough because we want more than that. But we are consistent."
An air of negativity has shrouded Arsenal after a trio of collapses, most recently in Saturday's defeat by Manchester United at home.
"Maybe we were the victims a little bit of our generous attitude going forward," Wenger said. "Tonight we had a bit more urgency to defend."
With fog descending on the Emirates Stadium, Sanogo quickly lifted the gloom. Santi Cazorla received a slick back pass from Sanogo and returned the favor to set up the striker to nutmeg goalkeeper Roman Weidenfeller with a low shot.
"What he did on the first goal was class but unfortunately he got injured," Wenger said.
The 21-year-old Sanogo was starting up front alongside Sanchez because Danny Welbeck is out with a knee injury and Olivier Giroud was ineligible after not being included in Arsenal's original squad for the group stage.
Arsenal also had to select its third-choice goalkeeper Emiliano Martinez, with Wojciech Szczesny joining David Ospina in the treatment room. Martinez prevented Dortmund from equalizing before halftime by denying Henrikh Mkhitaryan, and also made saves right at the end.
Sanchez sealed the victory in the 57th. The Chile forward curled the ball into the net for the 13th goal of his debut Arsenal campaign after being fed by Cazorla.