While all about him lost their heads, Cristiano Ronaldo kept his.
Yet again he stepped up for his club, Real Madrid, while Gianluigi Buffon, at the tail end of 17 seasons of loyal service to Juventus, let his down with a tantrum rightly punished with a red card.
Ronaldo showed he can wait, and not be tired of waiting, as Buffon's replacement, Wojciech Szczesny, took an age to ready his gloves and prepare himself for the penalty kick that referee Michael Oliver awarded correctly.
Ronaldo blocked out the din ringing around Madrid's Santiago Bernabeu Stadium, the bated-breath expectations of its 75,796 spectators focused only on him, the pressure of standing at the crossroads of triumph and disaster in the 97th minute of the Champions League quarterfinal second-leg match.
The spot kick, one of Ronaldo's finest, of course found the back of the net, just as the look of intense concentration on his face promised it would. Aimed with astounding accuracy and power into a 50-centimeter (20-inch) gap between the outstretched fingers of the diving Szczesny and his left-hand post, the goal gave Madrid a 4-3 aggregate victory on Wednesday night and a semifinal berth for the eighth straight season.
Off came Ronaldo's shirt in celebration.
It is tempting to roll one's eyes when he whips his kit off like this, peacocking his egg-carton stomach muscles to cameras and crowds. But think of those bumps and ridges he is so proud of this way: they're proof of how hard Ronaldo continues to work to stay on top, to prepare his body and mind for these key moments that separate great players from good ones.
In the latter stages of the 33-year-old's career, Ronaldo's untiring enthusiasm for football, the day-in, day-out seriousness and focus he continues to devote to his craft are mightily impressive. Every goal still clearly matters to him. The misses still hurt. His appetite for winning never seems satiated.
Although no longer quite as quick and light on his feet as he used to be, Ronaldo's stay-fresh dedication and footballing intelligence have pulled him level with Lionel Messi among club football's greatest-ever players and were showcased against Juventus in prime-time HD.
By going out of his mind when Oliver penalized Medhi Benatia's injury-time foul on Lucas Vazquez, Buffon made Ronaldo look even more icy-cool in comparison.
Ranting and railing at the referee with such wild-eyed fury had to be punished with a red card, even if it was Buffon's first in 117 Champions League games and, quite possibly, his last.
Had Buffon kept his head, perhaps he could have saved Ronaldo's penalty kick that put Juventus out. Certainly, Szczesny wouldn't have had to come on cold off the bench, leaving him even less chance of repelling Ronaldo.
But now, we'll never know. As Buffon melted down, Ronaldo calmly steeled himself, sizing up Szczesny's goal.
Watching from the sidelines, Madrid manager Zinedine Zidane could sympathize.
"He didn't deserve that," he said of Buffon's expulsion.
Because Zidane, too, famously hurt his team and himself by losing his head as a player. Had Zidane not been sent off for a furious head-butt in the 2006 World Cup final, depriving his team of its captain and his skills, perhaps France, not Italy, would have won the penalty shootout.
Again, we'll never know.
Ronaldo also has had "what if" bad-temper moments. Among them, a straight, late red for kicking Atletico Madrid captain Gabi Fernandez in the face in the Copa del Rey final in 2013. Had Ronaldo kept cool, had he been there to help his teammates in the last 10 minutes, might Madrid have prevented the 2-1 victory that ended Atletico's 25-game, 14-year winless streak against its rival?
Perhaps, perhaps not.
But this much, we do know: Against Juventus, Ronaldo fought with heart and nerve and sinew.
He kept his head while Buffon lost his and blamed others.
He expelled doubt and trusted himself.