The French striker netted the opener in the second minute at Emirates Stadium, before Alexis Sanchez made the win secure with his 13th goal of the season in the second half.
And Oxlade-Chamberlain was delighted to see Sanogo finally get off the mark in Arsenal colours.
“It’s important he got that goal, it’s been a long time coming,” said Oxlade-Chamberlain.
“In pre-season he showed us what he could do, and he took [the chance] tonight. It was a good start for him, a goal always helps your confidence and I thought he played really well.
“He held the ball up well and hopefully he can score a few more like that.
“Wins always relieve pressure,” he continued. “When we win everyone’s happy. The players, the manager, the staff and the fans are happy.
“There’s a long way to go in this competition and the league. We need to try to back this win up with some good results in the future.”
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