A howler by goalkeeper Tim Krul helped set Arsenal on their way to a win that lifts them up to seventh as bottom club Norwich City's hopes of staying in the Premier League faded further.
Dutchman Krul lost possession to Pierre-Emerick Aubameyang on the edge of his own penalty area for Arsenal's opener, the Gabon forward whipping the ball from his feet to score his 18th top-flight goal of the season.
Aubameyang then turned provider for Swiss midfielder Granit Xhaka to sweep home his first club goal since March 2019 before Aubameyang added another after a mistake by Josip Drmic.
Substitute Cedric Soares completed the rout, the substitute scoring from outside the penalty area four minutes after coming on for his Gunners debut.
Norwich, six points from safety with six games left, hit the woodwork through Ben Godfrey when the game was goalless, while Emiliano Martinez produced a fine save to keep out Kenny McLean's free-kick.
Reaction from the Emirates and the rest of Wednesday's Premier League gamesSaka signs new Arsenal contractAubameyang inspires Gunners
This was a highly satisfactory return to the Emirates Stadium for Mikel Arteta's side as they marked their first competitive home match since 7 March with an easy win.
Having lost their first two matches since the restart, the Gunners have now won their past three, have an FA Cup semi-final to look forward to, while Aubameyang is level on 19 goals with Leicester's Jamie Vardy at the top of the Premier League scoring charts.
His first was a gift, Krul easily dispossessed after a back pass by Godfrey as Aubameyang steamed in to score before laying on the pass for Xhaka to double the lead before half-time.
Another mistake, this time by Josip Drmic, allowed Aubameyang to pounce for the third, with Soares scoring the goal of the night from distance to complete an emphatic win.
Aubameyang, the fastest Arsenal player to 50 Premier League goals, is yet to pledge his long-term future to the Gunners, with his current contract due to expire in 2021.
The Gunners will hope he can be persuaded to stay after another inspirational performance by the forward, who has 51 league goals for Arsenal in 79 games.
Hope fading for Norwich
With three successive games against fellow strugglers Brighton (home), Watford (away) and West Ham (home) to come, Norwich will still believe they can turn it around.
But it looks increasingly likely the Canaries will be making a quick return to the Championship, which they won last season.
This was their fourth straight defeat since the re-start, while they have not scored a top-flight goal for more than six hours.
League defeat number 21 of the season was self-inflicted as mistakes by Krul and Drmic contributed to their latest downfall.
Boss Daniel Farke made a triple change at half-time and there was a brief period when Norwich looked like they might respond, but it was the same old story for the Canaries.
They are a team short of confidence while their leading scorer Teemu Pukki, one of the three players replaced at half-time, has not scored in his last 10 outings, playing 657 minutes, attempting 15 shots, with just five hitting the target.