Erling Haaland equalised early in the second half with a fine header, but Arsenal retook the lead one minute later through Thomas Partey’s deflected strike.
Lewis-Skelly’s brilliant effort gave them breathing space and Kai Havertz added a breakaway fourth before, deep in stoppage time, Nwaneri curled in spectacularly to complete the scoring.
It’s a good performance for Arteta’s men to stake claim as Arsenal prepares for a blockbuster Carabao cup semi-finals second leg match against Newcastle United on Tuesday having lost the first leg at the Emirates stadium two nil.