Both Paris Saint-Germain (PSG) and Chelsea booked their berths in the semi-finals of the Champions League with aggregate 3-2 and 2-1 victories against Bayern Munich and FC Porto respectively on Tuesday.
Paris Saint-Germain's relationship with the Champions League over the last decade has been fraught with disappointment and littered with spectacular defeats, but an aggregate victory against holders Bayern is the most significant of the Qatar era as they aim to finally get their hands on the trophy.
Against the team that Mauricio Pochettino kept insisting was the best in Europe, PSG exacted revenge for their 1-0 defeat in last season's final in Lisbon.
It was not achieved without suffering, as they followed their smash-and-grab 3-2 win in the first leg in the Munich snow last week with a 1-0 defeat in Tuesday's return, Eric Maxim Choupo-Moting scoring Bayern's goal against his old side.
But while in previous years PSG might have collapsed under the pressure, this time they held on to win their quarter-final tie on away goals sealed a semis berth.
Following the Qatar Sports Investments takeover of 2011, PSG spent a long time struggling to make an impact in Champions League knockout ties.
They threw away first-leg leads to lose on away goals to Chelsea in the 2014 quarter-finals and to Manchester United in the last 16 in 2019.
There was the humiliation of the "remontada" against Barcelona in 2017 too, when a 4-0 first-leg lead in the last 16 was obliterated in a 6-1 second-leg loss.
This time they held on, despite captain Marquinhos and playmaker Marco Verratti both missing the second leg, and despite Neymar missing a host of chances in the first half.
The success against the holders comes after they eliminated Barcelona in the last 16, winning 4-1 at the Camp Nou in the first leg.
That was also a case of exacting revenge, with the Catalans having beaten the French side in the knockout rounds three times in the previous decade.
In both of those ties PSG have shown a resilience that has been lacking before, and they have beaten two of the great traditional powerhouses of European football en route to the last four, having also beaten Manchester United away in the group phase.
Last year their run to the final, as impressive as it was, featured wins over Dortmund, Atalanta and RB Leipzig, none of whom were seen as contenders to win the trophy. The latter two victories came in one-off ties in the 'Final Eight' in Lisbon.
PSG's European run this season comes just as their hegemony at home is under threat -- after seven Ligue 1 titles in eight years, they are currently three points behind leaders Lille with six games remaining.
Nevertheless, the Champions League is really all that matters, and it is success in Europe's elite club competition that can convince superstar duo Kylian Mbappe and Neymar to sign contract extensions.
The two most expensive signings in football history when they arrived in Paris in 2017, Neymar and Mbappe are both out of contract at the end of next season. It remains Barcelona's dream to bring Neymar back, while Mbappe has long been linked to Real Madrid.
Porto's Luis Diaz (right) duels for the ball with Chelsea's Cesar Azpilicueta, left, and Chelsea's N'Golo Kante during their Champions League quarter final second leg match, AP
Meanwhile, Thomas Tuchel urged his young Chelsea team to embrace their Champions League "adventure" after they reached the semi-finals for the first time since 2014 despite a 1-0 defeat against Porto in Tuesday's quarter-final second leg.
Tuchel's side booked their berth after producing a masterclass in game management to win 2-1 on aggregate in Seville.
They could do worse than copy Tuchel's tactics as Chelsea smothered Porto with an intelligent defensive approach until Mehdi Taremi's stunning bicycle kick in the last minute of stoppage time.
That sublime strike was out of character with the rest of Porto's display as they laboured to overturn the 2-0 first-leg deficit.
Chelsea have lost only once in 18 matches since Tuchel replaced the sacked Frank Lampard in January and this was another feather in the German's cap.
Making it to the last four is an even more admirable feat given the lack of Champions League experience among the majority of Tuchel's squad.
Tuchel knows the likes of Mason Mount, Reece James, Kai Havertz, Ben Chilwell and Christian Pulisic are all learning on the job, but he hopes their fearlessness will be invaluable.
Tuchel had admitted this week was a make or break period for Chelsea.
They passed the first test and can now focus on Saturday's FA Cup semi-final against Premier League leaders Manchester City at Wembley before returning to the Champions League trail.
Tuchel this week said he wouldn't want to fight Antonio Rudiger or Cesar Azpilicueta, such is the ferocious will to win coursing through Chelsea's most vocal players.
Both defenders lived up to Tuchel's billing as they fought tooth and nail to keep Porto at bay in a niggly clash.
Porto manager Sergio Conceicao added: "I'm really frustrated but I'm proud of what we did in both matches.
Chelsea goalkeeper Edouard Mendy gifted Porto a golden opportunity for a priceless early goal when his miscued pass went straight to Jesus Corona inside the penalty area.
But Corona couldn't keep his composure and Jorginho did enough to ensure the shot flashed wide.
Corona's profligacy let Porto down again when he lashed hurriedly over from 12 yards after Ben Chilwell misjudged Otavio's high ball.
Taremi's eye-catching strike with seconds left came far too late for a dramatic finale, with tempers flaring in a heated exchange involving Rudiger and several Porto players after the final whistle.