Hazard scored twice past his former teammate as Chelsea sliced through Arsenal in the second half of the Europa League final, netting four times in the space of 23 minutes to win 4-1 in a London derby played far from home.
In an all-English rivalry, Chelsea won UEFA Europa League cup after beating Arsenal 4-1 in the final on Wednesday.
The championship match between the two London rivals were played at the Baku Olympic Stadium in Azerbaijan.
After a drab first half, Chelsea took control in the 49th minute when Olivier Giroud met Emerson's pass with a diving header into the net. It was the French striker's 11th goal in 14 games in the Europa League this season, but he barely celebrated against his old team, kneeling with palms raised as his teammates mobbed him.
Pedro doubled the lead when he found space in the penalty area in the 60th to stroke in a cut-back pass from Hazard.
It was soon 3-0 when Hazard converted a penalty after Ainsley Maitland-Niles — the only English player to start the all-English final — shoved Giroud in the box.
Two minutes after coming off the bench, Alex Iwobi punished Chelsea for a poor clearance with a volley from the edge of the box to make it 3-1 in the 69th.
But Arsenal's hopes of a comeback were extinguished three minutes later when Hazard and Giroud teamed up again. Hazard first passed the ball to Giroud and then knocked his flicked cross past Cech, the veteran goalkeeper who was playing his final game before retiring.
Arsenal's second 4-1 loss in final
Arsenal have never won the UEFA Europa League cup so far.
Turkish football giants Galatasaray beat Arsenal 4-1 in a penalty shoot-out in the 1999-2000 UEFA Europa League final.
It was the second time Arsenal played and lost in the UEFA Europa League final.
Arsenal also aimed to win the cup for the direct participation to the UEFA Champions League next season. After losing to Chelsea, Arsenal will go to the UEFA Europa League next season again.
Despite competing in seven finals, Arsenal hold only one UEFA cup, namely UEFA Winners' Cup in 1994.
Chelsea won 6 of 9 the UEFA finals and they won the Europa League cup for the second time in 2019 after reaching the victory in 2013.
With Liverpool and Tottenham meeting in the Champions League final in Madrid in June 1 and Chelsea and Arsenal played in the Europa League final, it marks the first time in history that Champions League and Europa League finals are contested by four English teams.