London: Chelsea secured a top-four Premier League finish and qualification for next season's Champions League after a 3-0 home win against Watford on Sunday.
Quickfire headers from Ruben Loftus-Cheek and David Luiz early in the second half put them in control and Argentine marksman Gonzalo Higuain added a third in the 75th minute.
However, Chelsea had to wait for Arsenal's 1-1 draw at home to Brighton & Hove Albion long after the final whistle at Stamford Bridge to confirm they would finish in the top four.
The battle for the third and fourth spots behind runaway leaders Liverpool and Manchester City had become a comedy of errors in recent weeks with all the contenders dropping points with reckless abandon.
And it was fifth-placed Arsenal's draw with Brighton that meant Chelsea would finish no lower than fourth - guaranteeing a return to Europe's elite club competition.
With one game left Chelsea are third with 71 points, a point clear of Tottenham Hotspur in fourth and four ahead of Arsenal.
It looked as though Chelsea were set to follow nine-man Tottenham's slip-up in a 1-0 defeat at Bournemouth on Saturday and Manchester United's earlier 1-1 draw at relegated Huddersfield as they struggled in a frenzied first half.
Watford had the better chances with Troy Deeney, Gerard Deulofeu and Jose Holebas all lively, but Chelsea, booed off at the break, came out flying in the second half.
Loftus-Cheek found the net in the 48th minute after a Hazard short corner and one-two with Pedro, the Belgian lifting the ball to the far post where the tall midfielder nodded it home.
Moments later Brazilian defender Luiz headed Chelsea's second goal, straight from a Hazard corner, before the home side improved their goal difference with the third from Higuain via a Pedro assist.
Both teams have preoccupations away from the league, with Chelsea level at 1-1 as they prepare to face Eintracht Frankfurt in their Europa League semi-final, second leg on Thursday and Watford meeting Manchester City in the FA Cup final on May 18.
"The schedule is tough, but when you have fantastic players, more than just 11, we can rotate and have the same quality," Luiz said. "We have that. It's tough but it's tough for everybody."
Chelsea's players and their families did a lap of honour after their last home league game of the season, with club captain Gary Cahill, who is leaving after 6-1/2 years at Stamford Bridge, leading his team mates out.
The former England defender won two Premier League titles, two FA Cups, a League Cup, a Champions League and a Europa League trophy with the west London club but has fallen out of favour under coach Maurizio Sarri this season.