MILFORD, England—WIMBLEDON At the All England Club, the weekend was a kaleidoscope of contrasts.

Historically, the first Sunday of the tournament at Wimbledon has been a day of rest, with no matches taking place. There are times when tradition is overtaken by time. Each Grand Slam tournament is now scheduling matches every day of the week, including weekends.

Nick Kyrgios and Stefanos Tsitsipas put on a mutually bratty display that you couldn’t get your eyes off, frequently for the wrong reasons, on the first Sunday of this year’s Australian Open.

Several hours after the celebrations and parade of champions that marked the 100th anniversary of Centre Court, two other luminous young talents, Jannik Sinner of Italy and Carlos Alcaraz of Spain, took to the most famous showplace in tennis.

Amid Kyrgios’ profanity and Tsitsipas’ erratic behavior, Sinner and Alcaraz showed why they were chosen to play on Centre Court, even though neither had ever played there before. ‘It’s a great honor to play on Centre Court,’ Alcaraz said.

In Sunday’s fourth-round match, the 20-year-old Sinner defeated the 19-year-old Alcaraz, 6-1 6-4 6-7 (8) 6-3, to show that they are both talented and classy well beyond their years.

Alcaraz came sprinting forward to give Sinner a fist bump after he got up after falling hard on his chest while trying to catch an Alcaraz drop shot.

Whether or not they are the future of men’s tennis remains to be seen. And it’s certainly the case, as evidenced by the fact that they’ve upset their elders and won tour titles, and advanced to the quarterfinals of Grand Slam tournaments at times. There are, however, no assurances. Injuries, large sums of money, and the arrival of new players can quickly alter the hierarchy.

After the match, Sinner said: “I think what we demonstrated today was a high level of tennis and an excellent attitude from both of us.” A lot of great tennis is still being played by a lot of other players. There is no doubt that we are the newest members of the group. What do you think? I have no idea what will transpire in the future. I think it’s great for tennis to have some new names and players..”

Having the No. 1 ranked Daniil Medvedev and his fellow Russians barred from playing due to the Ukraine conflict; the new No. 2 Alexander Zverev out after major ankle surgery; and three other leading grass-court players — Matteo Berrettini of Italy, Marin Cilic of Croatia, and Roberto Bautista Agut of Spain — withdrawing after testing positive for the coronavirus, this Wimbledon has been a strange one indeed.

Of the 16 men’s fourth-round players, only two (Novak Djokovic and Rafael Nadal) had previously advanced to the semifinals of a Grand Slam singles event. As a result of Djokovic’s 6-2, 4-6, 6-1, 6-2 victory over Dutch wild card Tim van Rijthoven on Sunday night, Sinner will face the three-time defending Wimbledon champion in the quarterfinals.

At the All England Club, Sinner had never previously won a match on grass in the main tour despite his seeding of 10. It was difficult to understand why after watching him maneuver the grass and generate enormous punching power with his groundstrokes against Alcaraz off shots hit from all sorts of different heights. Despite Sinner’s dominance, he was often the one who dictated the play against one of the most explosive men’s movers and hitters.

In his only previous tour-level match against Alcaraz, which Sinner had won, he kept him teetering on the edge of his seat and forced him to flick half-volleys while leaning back to keep the point.

Jannik “played incredibly well” for Alcaraz, the No. 5 seed, who described his performance.

While Alcaraz was frequently spectacular (he can’t help himself), he was also inconsistent, missing numerous drop shots and failing to convert any of his seven break points, while Sinner converted four of his 12 opportunities.

Those seemed to be the most important numbers in this case. Alcaraz’s groundstrokes went for too much, far too often. In the end, it was understandable to want to end the conversation. It was a testament to Alcaraz’s skill and competitive spirit that he turned what could have been a straight-set loss into something far more interesting.

Second-set tiebreaker: He fought off two match points before making a sharply-angled forehand half-volley drop shot winner at 8-8 of a full-force backhand passes down the line from Sinner that would have completed just about any other point.

Alcaraz finished the set by raising an arm and energizing the crowd, which didn’t require much more than that.

As a result, Alcaraz was unable to complete the comeback, double-faulting in the fourth set to lose his serve; even though he saved three match points on his serve in the eighth game, he could not stop Sinner from serving out the match.

A grass-court consultant hired by Sinner is Darren Cahill, a former player, veteran coach, an ESPN analyst. Cahill is helping him prepare for the matches, and they prepared well for Alcaraz, as Sinner handled the big stage and big moment with just a little more sang-froid.

Alcaraz, who is having a breakout season, stated, “I need to improve my mental stability.” There have been many highs and lows in today’s match, as there have been in numerous others. My nerves need to be better controlled. My day was ruined because of it.

As a result, he had to admit, that the Center Court assignment was a mistake.

In the classic quiet between points, “it’s not so much the court itself or the silence,” he said, referring to the typical silence.

With a grin, he said, “It wasn’t quite so quiet. Knowing the history of this court, however, is more exciting.” You’re taking part in a game while also being aware of the significance of the matches that have taken place there in the past. That was the weight on my shoulders.”

Wimbledon champions Billie Jean King and Rod Laver, as well as current champions Rafael Nadal, Novak Djokovic, Andy Murray, and Venus Williams, as well as retired champions like Federer and Djokovic, all played on the grass on this special Sunday.

“It was an honor for me to play in the Center Court for the first time today,” Sinner said.

This was his chance to shine and he and Alcaraz made the most of it.