Pierre-Emerick Aubameyang netted twice and Kieran Tierney grabbed his first Gunners goal in an action-packed finale to the league season at Emirates Stadium.
The goalmouth action started after just 34 seconds, when Alexandre Lacazette was bundled over for a penalty, and Aubameyang fired home the spot kick.
Tierney scored his first goal for the club soon afterwards and we were three goals to the good when Aubameyang netted an overhead kick.
But Watford were in no mood to give up their Premier League status without a fight, and got a goal back before half time through a Troy Deeney penalty.
Ex-Gunner Danny Welbeck made it 3-2 in the second half, but we held on to earn all three points and send the visitors down to the Championship.
You can watch bitesize highlights of our final home game of 2019/20 by clicking on the video above, while there are further highlights packages below plus first and second halves.
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