After a goalless first half at The Emirates, Lacazette came on for Danny Welbeck in the 61st minute in north London to help the Gunners push for the victory.
Arsenal went ahead when Pierre-Emerick Aubameyang fired home his penalty in the 76th minute, before the January signing made it 2-0 with a neat finish 10 minutes later.
And Lacazette then stepped up to score Arsenal’s second penalty of the afternoon in the 89th minute to wrap up all three points for Arsene Wenger’s men.
Lacazette has been out of action with a knee injury in recent weeks and had not featured since the 1-0 loss to Tottenham on 10 February.
And Arsenal legend Henry was clearly impressed with what he saw from his compatriot against the Potters on Sunday.
Speaking to Sky Sports after the game, Henry said: “He changed the game.
“When Aubameyang went on the left and Lacazette came on as a number nine, he started to make the runs that a number nine should make, running in behind and being available.
“For me, Lacazette changed the game when he came on.”
Arsenal will now switch their attentions towards their crunch Europa League clash against CSKA Moscow in the quarter-finals at The Emirates on Thursday night.
The Gunners remain in sixth place in the Premier League table.
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