When Denis Shapovalov stepped out to play Novak Djokovic in the semifinals at Wimbledon on Friday, the Canadian knew that to win he would probably have to play near-perfect tennis and take his chances.
For long periods of an enthralling battle on Centre Court, he managed the first task with some brilliant ball-striking and exhilarating hitting.
But when it really mattered, in the biggest moments, the door was shut in his face by the greatest defender the game has ever seen and a man whose resilience is as big a weapon as anything in the sport.
This was Novak Djokovic, not at his absolute fluent best, but mentally ruthless, smart and as stubborn as ever, cutting out the mistakes, daring his opponent to go for more, to push further, to go out of his comfort zone. All or nothing.
The left-handed Shapovalov, playing high-risk tennis, created numerous chances. The problem was that he couldn't take them, and though his explosive, exciting style had the crowd gasping at times, ultimately he lost in straight sets 7-6 (3), 7-5, 7-5.
"I don't think the scoreline says enough about the match," Djokovic said. "He served for the first set and he was probably the better player for much of the second set.
"But there's no holding back. Giving up is never a question."
Shapovalov was proud of the way he performed in his first Slam semifinal and the way he played suggests he could one day win a title. But Djokovic refused to be hit off the court, retrieved everything and even threw in serve-and-volley on big points, his tennis IQ kicking in on the biggest points, as always.
"Against Novak, you're going to have some chances that you're not going to get," said Shapovalov, who was in tears as he left the court, the realization that he was close to reaching a Slam final for the first time quickly kicking in.
"He does a really good job of putting pressure when it's needed, and you feel it exactly in those moments. He steps up. He does that really well.
"I had chances in every set. Just went his way today. I mean, obviously he's No. 1 in the world, so he's that for a reason. He's obviously played a lot of these matches, has a little bit more experience. Just played probably better, maybe a little bit lucky, luckier than me today in the bigger moments and that was it.
"I had a lot of chances. I was dictating [with] my game a lot. I thought he felt that. I did everything I could today, and it just didn't go my way. But I thought all three sets I had plenty of chances, plenty of break points. It just wasn't going my way."
"It's a learning process for me. Hopefully I can take a lot from this match and use it to keep going forward."
In this incredible era when the Big Three of Djokovic, Rafael Nadal and Roger Federer have won 59 of the past 71 Slams, the chances for the generations below them have been few and far between. Though their time at the top will come to an end sooner rather than later, Djokovic remains the ultimate challenge.
Every time Shapovalov thought he had him on the run -- and he had 11 break points -- Djokovic was there, rock-solid, refusing to budge, piling the pressure onto Shapovalov, who either missed or couldn't find the gap he required.
It is a resilience that is suffocating, and Djokovic keeps proving it, again and again, just as he did at Wimbledon in 2019, when Federer had two match points in the final set but could not put him away, the Serb going on to take the title for a fifth time.
Of course, Djokovic is also playing for a record-equaling 20th Grand Slam title and the third leg of the calendar-year Grand Slam, something no man has done since Rod Laver in 1969. He takes on Matteo Berrettini on Sunday.
It used to be said that beating Nadal on clay at Roland Garros was the toughest task in tennis. Perhaps beating Djokovic now, as he chases yet more glory, is the hardest thing anyone has ever had to do.