A campaign that began with the club's stadium turned over to UK health workers, took place almost entirely without crowds and shifted from high hopes to fears of abject failure ended with the Champions League trophy in Thomas Tuchel's hands in Porto – a victory, manager and even venue that no-one would have expected just four months ago.

Chelsea, as they so often have been since Tuchel became the surprise successor to axed club legend Frank Lampard at the end of January, looked tactically formidable at the setting hastily arranged because of the Covid-19 crisis in the original host city of Istanbul, although thousands of fans still made a logistically arduous trip to watch their team add to the club's history in Portugal.

They survived the early departure of defensive lynchpin Thiago Silva – thwarted by a painful-looking injury, but desperate to avoid a repeat of the defeat in the final he was part of with Tuchel at Paris last season – and scored an excellent goal at an ideal time, Havertz latching on to a masterful Mason Mount pass three minutes before the break.

"I waited a long time and now I've done it," Havertz told BT Sport of his supremely timely first Champions League goal.

"It's an incredible feeling. We deserved it. I don't give a f*ck about [my price tag] now.

Captain Azpilicueta grabbed Havertz. "He deserves it for a tough season, because of his mentality," beamed the skipper. "He's a superstar. He ran like crazy."

For a player as impactful as the young Germany playmaker was in the Bundesliga, Havertz has endured a torrid season, hampered by a long Covid-19 infection and a loss of form that may not have entirely been down to his illness.

Such were his performances in his homeland that there was little dispute over the need for Chelsea to break their club record transfer fee, signing him for what could amount to more than $100 million.

Perhaps the slice of luck Havertz received, seeing his initial shot after he had evaded Oleksandr Zinchenko blocked back into his path by onrushing goalkeeper Ederson to present him with an open goal, was deserved after his troubles. On the sideline, Tuchel could not contain his joy.

City steamrollered the Premier League in the second half of the season. There were almost no clear chances here, let alone rampages. Chelsea nullified the English champions, although there were inevitable scares: Azpilicueta cleared from under his own crossbar, and Andreas Christensen – Silva's replacement – blocked a Mahrez effort at close range.

Inspirational midfield orchestrator Kevin de Bruyne looked even more anguished than Silva had been as City were forced to replace him – justifiably, too, given a facial injury agonizing enough to leave him nursing a stream of blood with a towel from a seat.

His manager, Pep Guardiola, had started the evening determined to prove he could win the Champions League for the first time without the help of Lionel Messi, and there must have been times when he wished he could count on the split seconds of magic his former striker can create to complete seemingly impossible missions against defenses of the kind organized by Tuchel.

As usual, the team that claimed fourth place in their domestic league by virtue of Tottenham beating Leicester remained willing and vibrant on the counterattack.

Tuchel covered his face with his hands and sunk to his knees after Christian Pulisic reached a Havertz pass with only Ederson to beat on the edge of the penalty area, N'Golo Kante having shown typical tenacity to win possession in a dangerous area, starting the move which the American ended by rolling his shot wide of the far post.

That was the last major chance. Chelsea, who had looked like a team heading towards midtable with little prospect of troubling the heavyweights of Europe at the start of the year, had done it again, repeating their feat of 2012, when they beat Bayern Munich in Germany.

Zinchenko was among the City stars in tears as Guardiola's squad received their medals. There was to be no final glorious swansong for the sobbing Sergio Aguero, the club's top scorer who is heading to Barcelona to join Messi after an exceptional career at the City of Manchester Stadium.

Speaking earlier this season, one of the reasons Abramovich said he still loves the game was its unpredictability. Even with such an expensively-assembled squad of talents, Chelsea were outsiders to win the most prized trophy in Europe until recently, and most would have tipped the Russian to witness his second defeat in a final following the penalty exit at the last to Manchester United to Moscow in 2008.

His acquisitions of Tuchel and Havertz now look like masterstrokes that even he might not have expected to pay off as handsomely as they have.