On 54 minutes, Romelu Lukaku’s spectacular header gave the European champions the lead, but Raphael Veiga equalized for the Copa Libertadores winners shortly after the hour mark in Abu Dhabi.
Havertz, who scored the game-winning goal in the Champions League final against Manchester City, was the match-winner for Chelsea once more after converting a penalty awarded after a VAR review on 117 minutes.
“It’s incredible.” We are now world champions after being European champions. Havertz told Channel 4 that it “sounds better.”
“I was nervous [taking the penalty], I have to be honest. It’s a big penalty. It’s just crazy. It was good I kept the nerves. I am very happy. I dreamed always as a kid of this. This is an amazing feeling for me.”
Chelsea were crowned world champions for the first time in their history.
The Blues have now claimed every possible trophy since Roman Abramovich bought the club in 2003, and become the third English side to win the global tournament after Manchester United and Liverpool.
Chelsea avenged their 1-0 loss to Corinthians in the 2012 final, but will have little time to celebrate with a critical stretch on the horizon once they return to London.
They face Lille in the Champions League last 16 either side of the League Cup final against Liverpool and FA Cup fifth round, playing in four different competitions in 12 days.
Chelsea coach Thomas Tuchel was back in the dugout having flown out to Abu Dhabi on Friday after missing the past two games following a positive test for COVID-19.
Edouard Mendy returned in goal in the wake of Senegal’s Africa Cup of Nations victory, at the expense of Kepa Arrizabalaga, whose much-improved form is likely to attract interest from other clubs in the European transfer summer.
Chelsea’s decline in the Premier League has coincided with a lack of authority and conviction, and despite controlling possession it was not until the end of the first half they forced Weverton Pereira da Silva into a save.
Even then, Thiago Silva’s searing drive from distance appeared to be going wide.
In contrast, Palmeiras were twice left to rue their lack of efficiency as Dudu stabbed well wide before Andreas Christensen made a key intervention to negate a promising attack for the Brazilians.
Lukaku has struggled to meet expectations after rejoining Chelsea from Inter Milan as the club’s record signing, but the Belgian made it two goals in as many games here early in the second half.
Callum Hudson-Odoi, given the nod at left wing-back, whipped in a cross and Lukaku soared above two defenders to power beyond Weverton.
Christian Pulisic, brought on 30 minutes in for the injured Mason Mount, curled just wide after tidy interplay with Lukaku, but Chelsea gave Palmeiras a way back in when Silva handled in the area.
Australian referee Chris Beath was recommended to review the incident on the touchline monitor as Palmeiras players and coach Abel Ferreira appealed, and he almost immediately pointed to the spot.
Veiga, on target in the 2-0 win over Al Ahly, held his nerve to slam the penalty beyond Mendy, greeted with bellowing roars from many of the near-capacity 32,871 in attendance the majority wearing the green and white of Palmeiras.
Pulisic again rolled an effort narrowly wide from an inviting lay-off and extra time came as little surprise, Chelsea were forced to play an extra 30 minutes for the second time in a week.
A frantic scramble inside the six-yard box saw Pulisic bundle against the bar, although an offside in the build-up would have ruled out any goal.
Timo Werner curled over as time ticked away and Palmeiras defended deep, but Chelsea got the late breakthrough when Luan was penalized for blocking Cesar Azpilicueta’s volley with his arm.
Havertz sent Weverton the wrong way to spark wild celebrations, and a bitter night for Palmeiras culminated in them finishing with 10 men after Luan was sent off for scything down the German.
European champion, UEFA Super Cup winner and now club world champion. It has been quite the start to the tenure of Tuchel.
Chelsea is the ninth straight European winner of the title, dating to 2013. The last team from Europe to lose in the final? Chelsea to Corinthians in 2012.