The Champions League is a competition defined by big moments. These are often highlight-reel goals scored by the game's very best. Or wonderful pieces of skill that are repeated in school playgrounds across the world.
But every now and then, the match-altering incidents take place away from the attacking third. And that was the case at Stamford Bridge this evening.
Chelsea are through to the Champions League final. Let that sink in for a moment. A campaign that was coming off the rails in January will now end with the Blues competing for the biggest prize in club football at the end of this month.
Much of the credit for the dramatic turnaround goes to Thomas Tuchel. His appointment at the end of January resulted in an instant upturn in form and performance. Chelsea have only gone from strength to strength under the German coach.
Against Real Madrid this evening, the Blues were imperious. They dominated the 90 minutes at Stamford Bridge, fashioned chance after chance.
What was frustrating is how few were taken. On paper, goals from Timo Werner and Mason Mount were the difference between the two sides. In reality, there was a chasm in quality.
Yet it could've all been so different for Chelsea, could've all been so much harder, had the most underrated player in the Chelsea team not produced a defining moment when it mattered most.
We're not talking about Kai Havertz. Nor Timo Werner. And N'Golo Kante isn't underrated. No, we are talking about Edouard Mendy.
The Senegal international arrived at Stamford Bridge last summer to little fanfare yet his signing was arguably one of the most important of a busy transfer window.
Mendy was charged with replacing Kepa Arrizabalga in the Chelsea goal. He quite simply had to step up; there was plenty of pressure on the 29-year-old.
It didn't impact him. Mendy has been understated but effective. The goalkeeping concerns the Blues had 12 months ago quickly erased.
“He is a good age for a goalkeeper,” Petr Cech, arguably Chelsea's greatest ever goalkeeper, told BT Sport ahead of tonight's game.
“His personality is very calm and he wants to be better every day. I think every day he works and that’s key for him. So far, I think it’s been a great campaign from him, from everybody.”
Perhaps what Mendy, who was signed on the recommendation of Cech, needed was a performance on the biggest stage, a game in which his undoubted quality should shine through. That arrived tonight.
Chelsea may have dominated the contest but they did concede two big chances. The first of which arrived moments before Werner struck. Karim Benzema received the ball on the edge of the Real Madrid penalty area, turned and whipped a shot towards the corner.
It was destined for the Chelsea net yet Mendy flung himself across goal, used every inch of his 6ft 6ins frame, and tipped the ball wide of his post.
It was a huge stop and moments before half-time, Mendy repeated the trick. Benzema managed to escape the attention of the Blues' three centre-backs as a cross came into the penalty area and connected with a header.
Again, the ball was headed for the back of the Chelsea net but Mendy reacted quickly to arch his back and push Benzema's effort over the crossbar.
Without those two saves, the Blues don't win the game and they don't book their place in Istanbul. Mendy was the difference.
"We can't forget the two saves from Edou in the first half," club captain Cesar Azpilicueta said after the game. Chelsea supporters certainly won't.
