Newcastle had the better of the first half but could not test keeper Petr Cech often enough to get themselves in front, and they were made to pay within four minutes of the restart when Xhaka curled home a fine free-kick.
"Torreira made a difference when he came on at half-time".More news: Formula 1 Ferrari Concept Car Shown by Ross Brawn in Singapore
"The difference that was he looked forward so quickly. That was the big difference".
There has been speculation over Ozil's relationship with Emery since the Arsenal manager took him off at the hour mark against Chelsea last month, but the player clarified that he is delighted to play for the new manager and has a good relationship with him.
Speaking after the clash, Emery admitted his side still had work to do despite their upturn in form.More news: Needles found in Gladstone family's strawberries
"We are happy with this victory and we are improving but we also need to continue working individually and collectively to improve more things".
Emery said: "In the first half, we couldn't control the match like we wanted and we needed that control to impose our ideas, our possession and our positioning".
'The second half went very well for us and I think it was an important three points for us.
Pierre-Emerick Aubameyang failed to test Dubravka from seven yards out after Lacazette played him into space on the left, while Lucas Torreira skied a first-time effort from 19 yards out after being teed up by Ozil on 71 minutes.More news: Recalled Sane sets City on way to win over Fulham
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