The Gunners, who had been leapfrogged into second place by Brighton earlier on Sunday, closed the gap at the top of the Premier League on Manchester City as the former Chelsea winger popped up with a late winner via a deflection from Jair Cunha.
The north Londoners had been frustrated by a disciplined Forest throughout, while the hosts threatened themselves in a cagey affair on Trentside.
Mikel Arteta won’t care about though, as the champions continue their winning run ahead of their Champions League clash against Bayern Munich next week.
More to follow.