Watford signaled their intent early on and gave Everton a scare early on after an innocuous ball fizzed across the face of Tim Howard's goal with Phil Neville clearing.
James Beattie, Andy Johnson and Simon Davies linked well as Everton replied but Lee Carsley's cross found only Ben Foster's hands
Ashley Young drove a fierce shot at Howard after neat play by Darius Henderson, but the Everton keeper parried to Joseph Yobo who scissor kicked the ball to safety.
Stubbs fouled Shittu close to Everton's area but Marlon King fired tamely at the wall.
Andy Johnson went on a trademark run, but Lloyd Doyley beat an incoming Simon Davies to the punch.
A minute later Spaniard Mikel Arteta unleashed a fierce drive which went narrowly over the Watford goal as Everton began to turn the screw.
After a barren pre-season, Andy Johnson scored his debut goal for the Toffees as he latched onto a fifteenth minute Beattie ball and lobbed Foster from 20 yards.
Watford were up for a challenge though and went close on twenty three after a goalmouth scramble ended when Arteta guided a loose ball to grateful keeper Howard.
Watford's physical approach showed when they won the first corner but Carsley easily cleared Young's kick.
Shittu maybe should have had his marching orders after bringing down Johnson as the last man but received only a yellow on thirty six.
Francis was booked minutes later after felling Valente. Cahill almost made it two from Arteta's excellent free kick.
Ref Walton was booed loudly after booking a bemused Beattie for apparently not retreating quickly enough into his own half.
SECOND HALF
Marriapa made way for Jay DeMerit as Watford looked to claw back the deficit.
Valente couldn't shake the injury he picked up in the first half and allowed Joleon Lescott his first taste of Premiership action.
Watford started in similar fashion to the first half but in truth Everton did not seem too shaken.
Beattie should have made it 2-0 after fifty seven minutes but scuffed a Johnson cross from 3 yards out.
Ashley Young at the other end could have got himself on the score sheet, but brave veteran Stubbs threw himself between ball and net.
Francis missed the target with a week shot after Henderson stumbled his way into Everton's penalty area.
The game began to lose its earlier sparkle and Stubbs gave away a needless corner after a mix-up with Howard on sixty eight.
Priskin was brought on to inject some pace in the closing stages but lost the ball with his first touch and then conceded a foul.
Everton wrapped things up after Powell handled in his own area on eighty two under pressure from Cahill. Arteta stroked the ball home from the spot kick.
Everton did their usual capitulation act in injury time as Priskin set up Francis who nestled the ball into the Everton goal in injury time to set up a tense finish, though the Blues hung on.
No doubt Everton deserved the win but Watford showed enough to suggest the may not be the whipping boys the rest of the league expects.