Ross Barkley sealed the win, piercing through an empty Watford midfield before firing home from distance. The result sees Everton stay seventh, where they will finish the season.
Lively first half
Everton opened as the stronger side, and had the first chance after some clever play between Idrissa Gana Gueye and Ross Barkley outside the area, which allowed Barkley to jink inside and curl a shot that was well saved by Heurelho Gomes.
The game could be both Barkley and Romelu Lukaku's last as Everton players at Goodison Park, seeing as Lukaku has been strongly linked with a move away and manager Ronald Koeman recently issued Barkley an ultimatum over a new contract.
The ultimatum was quite an interesting tactic, as his decision-making has never been one of Barkley's strengths.
Watford opted for a pairing of Troy Deeney and Stephano Okaka up front, leaving M'Baye Niang on the bench. It appeared as if manager Walter Mazzarri felt more confident in a battle of physicality against Ashley Williams and Phil Jagielka.
With just one goal in their last eight hours and 11 minutes of playing time before this game, it was understandable that Mazzarri felt the need for a change. Everton then had a chance from a corner after the ball fell to Tom Davies a few yards out from goal, his clawed effort was tipped away by Gomes though.
Okaka was then able to dribble the length of Everton's half before teeing up an effort that sliced just wide of goal. Everton were able to find their groove early on in an action-packed first half, Davies had a good effort from 20 yards saved after a smart Barkley flick-on.
Second half well executed by home side
Everton came out strong in the second half, and made a positive change with Enner Valencia coming on for Mason Holgate.
Watford had a golden chance just seven minutes into the second half though, Deeney firing wide from inside the area after a good run by Jose Holebas.
Everton took the lead moments later though through a wonderful finish from Barkley.
The midfielder brought the ball up the field through Watford's half with no man closing him down, before firing home from 25 yards.
Kevin Mirallas then had a shot parried to the feet of Lukaku who was then adjudged to have been brought down in the box but the referee decided against giving a penalty, just before Morgan Schneiderlin met Leighton Baines' cross with a header that flew just over.
The midfielder then went to the other end of the field and made a vital interception to deny Okaka an equalising goal.
Watford's best chance fell to Okaka in the last five minutes, bringing down a Nordin Amrabat cross before volleying well before Joel Robles pushed the effort wide.
Valencia almost finished the game off going one-on-one with Gomes but after some good defensive pressure his effort was tipped wide.
Watford pushed a bit more for an equalising goal as the clock ticked down, but it was a deserved victory for Everton.