No team had managed to defend a Champions League title until Zinedine Zidane's Real Madrid did so in 2017, and although winning it for a third time in a row seemed equally unthinkable, last season in Kiev Los Blancos made history again.
Now the challenge is to move within reach of the Real Madrid side that won the first five editions of the old European Cup, but that will be very tough without Cristiano Ronaldo and Zidane.
That said, this is a team full of champions who will feel extra motivated by the prospect of winning Europe's most prestigious trophy on enemy soil, with the final taking place in the Estadio Wanda Metropolitano on June 1.
This time, the pressure is on an Atletico Madrid side that has strengthened like never before, breaking their record transfer fee to sign Thomas Lemar, and keeping hold of key players like Antoine Griezmann and Jan Oblak.
The rojiblancos will know that hosting a final doesn't go hand-in-hand with winning it though as Bayern Munich can testify, having dominated their 2012 showdown with Chelsea before losing on penalties in their own stadium.
Real Madrid and Inter are the only teams to have managed such a feat, but that happened way back in 1957 and 1965 respectively.
Spain will host a Champions League final for the first time in nine years, after Inter defeated Bayern in the Estadio Santiago Bernabeu with Jose Mourinho in charge in 2010.
The Wanda Metropolitano is the perfect stage and the most modern stadium the country has to offer, but competition is rife as Leo Messi and Barcelona will give everything to lift the trophy once more, while Valencia will dream of getting to the final again as they did in 2000 and 2001.
The special format of the Champions League means clashes between big clubs are likely as are potentially unfriendly reunions between teams and their former players.
For Real the group stages could see possible meetings with Porto's Iker Casillas, Manchester United's Jose Mourinho, Napoli's Carlo Ancelotti, Liverpool and Jurgen Klopp or Mauricio Pochettino's Tottenham.
Barcelona could once again face Monchi's Roma, after the Italians that eliminated them last time out, or Harry Kane's Tottenham, who might be the toughest opponent as well as the danger of confronting Liverpool, who, sitting in pot three, could be drawn against any of Spain's top three clubs.
The presence of the likes of Bayern, Manchester City, Juventus and Paris Saint-Germain in pot one makes it a slightly less daunting prospect.
Finally, Valencia find themselves in pot three which could mean a trickier draw than their Spanish rivals although at least they will avoid Liverpool.