Arsene Wenger wanted a No 9 and he has one. The Frenchman was exactly where he had to be inside the box to side-foot a composed finish into the bottom corner.
Alex Oxlade-Chamberlain worked well down the right before picking out Welbeck in the middle. The former United man scuffed his effort but it fell kindly to Lacazette who did the rest.
He is off the mark at the Emirates and Wenger will be delighted.