Kieran Tierney added a second, before throwing the ball in for Aubameyang to make it 3-0 with a well-taken overhead kick, though Troy Deeney pulled one back before half-time with an effort of his own from the spot.
Things got even closer when Danny Welbeck scored. But while Watford continued to put plenty of pressure on going into the latter stages, Arsenal hung on to end their season with a 3-2 victory, condemning the Hornets to relegation.
The Gunners got off to a very quick start, which is always a bonus -- especially so in games where it would be easy for them to relax. They were able to control the ball for long periods, especially in the first half. Their attackers showed a clinical touch in the opposition box with the majority of their chances. Not performing at their best and still getting the three points can also be seen as a positive.
There were definitely signs of defensive calamity, which resulted in Watford carving them open far too easily at times. While Arsenal managed to get the three points, there were periods in which they seemed to lose intensity, though that is perhaps understandable given the situation. It will be concerning how much they struggled once Watford scored their second.
Manager rating out of 10
6 -- Mikel Arteta took the game seriously (which some managers may not have done with a cup final around the corner) and got the win. His direction during the first break seemed pivotal, as the Gunners executed the initial tactical plan after it far better than they had from the start. His decision to deploy five at the back only seemed to put Arsenal under extra pressure.
Player ratings (1-10; 10 = best. Players introduced after 70 minutes get no rating)
GK Emiliano Martinez, 8 -- Assured whenever called upon, there wasn't too much he could do for either of Watford's goals. He made a superb save to deny Welbeck his second of the game. Was booked for time wasting.
DF Rob Holding, 6 -- It was his poor pass that eventually led to Watford getting on the score sheet. He looked solid throughout the majority of the game, but did have some shaky moments.
DF David Luiz, 4 -- Gave away his fifth penalty of the season with a silly attempt at a tackle on Welbeck. His positioning for the former Arsenal man's goal was poor, and there were other balls into the box that he could have been more assertive in dealing with.
DF Kieran Tierney, 8 -- Got Arsenal's second goal with a side-footed effort, and repaid Aubameyang for setting him up by assisting Arsenal's third with a long throw. He also did a good job of dealing with Ismaila Sarr when playing directly against him in a back four.
MF Joe Willock, 6 -- He is likely one of those that was playing for their place in the FA Cup final and he did show bright moments, often looking positive in his play. However, he struggled to make any clear-cut chances.
MF Dani Ceballos, 7 -- The Spaniard played with real freedom in his passing in the first half. He also produced an important block to deny Abdoulaye Doucoure. However, he struggled to have the same impact when it was a two-man midfield.
MF Granit Xhaka, 7 -- Talked his way into receiving a stupid booking, but showed confidence in his general performance, helping his team get over the line.
FW Pierre-Emerick Aubameyang, 9 -- Had the perfect start to this game, clinically scoring from the penalty spot, before calmly assisting Tierney's goal. He then added a delightful overhead kick for the third. He even put in good work defensively in a superb performance, though he couldn't take his chance to get a hat trick and seal the Golden Boot.
FW Alexandre Lacazette, 7 -- Won a penalty in the opening minute and put in plenty of selfless work throughout his time on the pitch.
FW Nicolas Pepe, 7 -- Drove at Adam Masina well and posed a threat at times, which was epitomised when Will Hughes felt the need to cynically bring him down near the halfway line and pick up a yellow card.
Eddie Nketiah, 6 -- Replaced Lacazette in the 57th minute and could have scored, but tried to assist Aubameyang. Put in a good shift.
Sead Kolasinac, 5 -- Replaced Willock in the 57th minute and struggled to contain Sarr.
Lucas Torreira, N/R - Replaced Ceballos in the 71st minute and showed his usual level of desire to help see out the game, though he gave a free-kick away in a dangerous area late on.