West Ham captain Mark Noble scored a goal in each half as West Ham beat Watford 4-1 on the final day of the Premier League season, leapfrogging their opponents to claim 10th spot with 52 points.
With next week's FA Cup final against Manchester City still to come, Watford's defending was lacking in intensity and they ended the league season two points further back in 11th position.
Noble put the visitors ahead in the 15th minute and Manuel Lanzini made it two shortly before half-time, heading into an empty net with the defence caught flat-footed after Michail Antonio had thumped a shot off the crossbar.
The second half had barely got under way when Gerard Deulofeu pulled one back for the home side, snapping up an under-hit back pass by Pablo Zabaleta and poking the ball past Lukasz Fabianski before firing into the net.
Any hope of a Watford comeback was snuffed out when full-back Jose Holebas was shown a straight red card for his last-ditch challenge on Antonio, which will see him suspended for the cup final.
Watford seemed incapable of learning from their mistakes, and West Ham's third came from another rebound, Marko Arnautovic firing in his 10th of the season before Noble rifled home a penalty to complete the rout 12 minutes from time.