Kylian Mbappe showing at World Cup he's ready to inherit the crown of Messi and Ronaldo

In years to come, we might remember the knockout rounds of the 2018 World Cup as the moment the baton of the world's greatest player was passed onto its next superstar. After a decade of dominance from Lionel Messi and Cristiano Ronaldo, after a thousand debates over which is superior, on Saturday they were united in misery. Messi's Argentina were out. Ronaldo's Portugal were out. But Kylian Mbappe's France were through.

Mbappe was already a star at club level, after two excellent seasons with Monaco and Paris Saint-Germain, but ultimately he's very new to international football. A year ago, Mbappe had never scored for his national side. Now, after two years of Didier Deschamps obsessing over whether France should be based around Antoine Griezmann or Paul Pogba, suddenly Mbappe is the main man.

With Messi and Ronaldo out of contention, bookmakers now consider him the favourite to win this tournament's Golden Ball, awarded to the World Cup's best player. Amazingly, Mbappe has only really shone in one match so far, but that summarises his extraordinary level of performance in France's 4-3 victory over Argentina.

Mbappe's display was a two-part act: He ripped into Argentina in the first half to put France on the front foot, and then sealed the game himself after the break. Few players in this tournament have been capable of playing both roles, putting their side in charge and then putting their side in front. It was, for that reason, the standout performance of the tournament so far.

World Cup 2018 must-reads

- Make your daily ESPN FC Match Predictor picks!
- World Cup fixtures, results and coverage

- World Cup Daily live: Follow the action with ESPN
- Why has World Cup been full of surprises?
- Ronaldo, Messi finally have rivals for Ballon d'Or
- England must create more chances against Sweden

With Argentina playing a 4-3-3 and offering left-back Nicolas Tagliafico no protection whatsoever, Mbappe was afforded far too much space from his right-sided position, and France's general approach was simple: find Mbappe, and let him run. The game's first significant incident came when Javier Mascherano clumsily fouled Mbappe, allowing Griezmann to step up and fire the resulting free kick against the crossbar. That was the early warning sign. Argentina didn't learn their lesson.

Minutes later, Mbappe was first onto a loose ball inside his own half, and within eight seconds had dribbled almost the length of the pitch before being taken down inside the penalty area by Marcos Rojo. It was a frightening demonstration of pure speed, taking Mbappe easily past opponents and forcing Rojo into a completely pointless foul. Griezmann scored from the spot, and France were 1-0 ahead.

The same pattern continued. With Mbappe making a run in behind the defence, rather than dribbling through it himself, he was found by Pogba's booming pass, with Tagliafico taking his turn to foul France's No. 10. A free kick was awarded, right on the edge of the box. Pogba fired over.

Argentina battled back, briefly going ahead. Mbappe's opportunities to counterattack were limited by Ever Banega shifting across, even if he was cautioned for his first challenge of the second half.

But now, having used his speed primarily to win fouls in dangerous positions, at 2-2 Mbappe took his opportunity to strike. In the first half, his straight-line speed over long distances proved crucial. Now, he unlocked Argentina's defence with his acceleration over five yards, finding space to fire home. Franco Armani should have saved Mbappe's low shot, but the speed of his movement meant the goalkeeper wasn't properly set.

Then came the clinching goal, France's fourth. A flowing move that involved Blaise Matuidi, Pogba, Griezmann and Olivier Giroud ended with Mbappe steaming in from the right flank, with a diagonal run from touchline to the corner of the box. The angle of his finish was perfectly in line with his run, almost an afterthought and the consequence of his momentum. For all the comparison to Thierry Henry, he generally finished from an inside-left position, whereas Mbappe is happy going across the goalkeeper from the other flank.

While other young superstars often need their individual talent converted into something more selfless, Mbappe is a team player. When others might have gone for their hat trick, he attempted to square for Griezmann. Perhaps he actually needs to become more selfish, more clinical, not simply to fulfill his vast potential but because he's so consistent when pulling the trigger.

Mbappe's performance against Argentina was reminiscent of Michael Owen's against the same opposition in 1998, although he's also prompting comparisons to another legendary forward from that tournament.

"He has qualities similar to Ronaldo, the Brazilian, but he's also something different," said teammate Raphael Varane afterward. "He likes dribbling, he's learning and we're happy to have a player like him."

Some rumours suggest Mbappe might soon be a teammate of Varane's at club level, too, with Real Madrid releasing a statement -- presumably a tactical move -- denying they'd agreed to a deal for his talents. But it would be a logical step. Real are desperate to snap up the superstar from every World Cup: Ronaldo in 2002, Fabio Cannavaro in 2006, Mesut Ozil in 2010, James Rodriguez and Toni Kroos in 2014. Real are obsessed with having the world's greatest player at their club. Soon, the world's greatest might be Mbappe.

The accepted approach with a player like Mbappe, still only 19, is to ponder how good he might become when he reaches his peak. But the likes of Owen and Ronaldo, players who depended upon sensational explosive speed, offer a cautionary tale. Owen won the Ballon d'Or at the age of 21, although he believes he peaked a couple of seasons earlier. Ronaldo was a considerably better player when he won the Ballon d'Or for the first time at 21 in 1997, rather than when he triumphed five years later at 26, as a slower, less mobile striker.

Mbappe might become better throughout his career. But there's every chance that this is Mbappe's best opportunity to shine, in peak physical condition for a player in his mould, and with Griezmann and Pogba carrying more pressure and expectation. A defensive-minded and compact Uruguay will be a much tougher test than a disorganised Argentina, and Mbappe must showcase his intelligence more than his speed: a microcosm of his challenge in the next few years, when his physical traits might decline, and his footballing brain will determine his longevity and legacy.