Olivier Giroud came on with the Arsenal fans fearing the worst, after Sunderland had just equalised, despite barely threatening for the first hour of this Premier League match at the Stadium of Light. They needn't have worried. Because, with his first two touches of the game, the striker scored two delightfully-taken goals and easy as pie Arsenal turned a possibly-forgettable fixture into a rout.
Alexis Sanchez opened the scoring for the Gunners with a nice header in the first half, and after the Chilean was denied a penalty by Martin Atkinson, the referee gave a spotkick at the other end, after Duncan Watmore, running onto the ball following a mistake from Shkodran Mustafi, was brought down by Petr Cech.
Jermain Defoe made no mistake with his penalty, smashing it to the top corner to level the game up on 65 minutes and give the Sunderland fans (and Tottenham's) something to smile about.
Wenger decided it was time for a bit of a physical presence up front, and Giroud, who might have even started this game, came on to rescue Arsenal, and then some.
The go-ahead goal was scored in the 71st minute, a wonderfully-guided left-footed finish from the Frenchman off a pinpoint cross from the excellent Kieran Gibbs, filling in at left-back for the injured Nacho Monreal.
Five minutes later, Giroud had his second, a centre-forward's glanced header off a corner. Giroud got in front of his marker Papy Djilobodji at the near post and then put in a beautiful, flicked header which arched over the Sunderland goalkeeper Jordan Pickford.
Two more minutes in and it was 4-1 to Arsenal. After Gibbs struck the post off a shot from an angle, Aaron Ramsey's scuffed shot fell to Sanchez, who pirouetted past a couple of defenders before stabbing the ball into the back of the net.
Unable to believe how the match had unravelled in such a hurry, the Sunderland fans made their exits as David Moyes sat on the bench, shell-shocked and wondering just how on earth he is going to turn this around.
Other results: Middlesbrough 2-0 Bournemouth; Tottenham 1-1 Leicester City; West Bromwich Albion 0-4 Manchester City; Manchester United 0-0 Burnley; Watford 1-0 Hull City.