For the first time in his career, Carlos Alcaraz got the better of Félix Auger-Aliassime on Thursday evening, in two identical sets of 6-4, in the most anticipated duel of the day at the Indian Wells tournament.

The margin is very thin, even tiny, between the game of Auger-Aliassime and Alcaraz. These two players should meet again before long in the final of a Grand Slam tournament.

This clash, however, demonstrated the difference between a player with world No. 1 within reach and a player struggling to stay in the top 10.

Before this quarter-final match, the Quebecer had a perfect record of three wins in three games against the Spaniard. The stakes, however, were quite different for the two protagonists. Auger-Aliassime was trying to save his start to the season, while Alcaraz wanted to continue his journey to the top of the world rankings, which he will regain if he wins the tournament.

After 120 minutes, the El Palmar prodigy came out on top, simply because he was almost perfect. He was offensive and powerful. Explosive and giant. He was the bully and the Quebecer could only see the damage.

This season, Alcaraz is the best returner on the circuit. He proved it once again on Thursday by winning twice as many points as his opponent in return of service. Truth be told, even on serve, the Spaniard excelled. After three service games, he had won all his points on the first serve.

Even though he was playing against his pet peeve, the 19-year-old was inventive at his leisure. He placed himself in different places to serve, he varied the effects of his balls and he handcuffed the Quebecer, especially on the forehand, yet Auger-Aliassime’s anchor point in return.

Alcaraz stood out more for his explosiveness at the net. Clearly, he detected a flaw in the game of his rival. This match was played on the climbs, to the advantage of the tenth racket in the world. His tactical schemes were clear and well defined.

Auger-Aliassime was helpless. Although the latter returned slaps along the line at more than 90 miles an hour, Alcaraz was already at the net, agile and delicate as a cat, tenderly depositing the ball on a cut backhand, unreachable for Auger-Aliassime , out of resources.

Even if it was less clean at the start of the second run, Alcaraz had the wind in its sails from boarding until arriving at the quay.

Two broken. There was no need for more. This is the only stat that really cost Auger-Aliassime the game. For the first time since the start of his career, his serve is letting him down.

When he serves as he is able, the Quebecer can beat anyone on this planet. It is his main weapon. A Félix Auger-Aliassime without his service is a Marc Arcand without his nunchakus.

However, since the start of the tournament, this crucial phase of the game has made things complicated. This had been the case against Francisco Cerundolo and against Tommy Paul. The troubles continued against Alcaraz. Auger-Aliassime passed just 56% of his first serves, won just 71% of his first-serving runs, and barely broke the 50% mark for second-serving runs. Abnormally low yield. And it’s not just because the California surface is exceptionally slow.

Still, with better serving numbers, the 22-year-old could have competed more with his rival. The Quebecer was not downgraded. Far from there. On the other hand, his shortcomings have been highlighted by his opponent.

However, he fought well. Before getting broken for the first time, he had saved four break points. Much the same way he had saved six match points against Paul.

His snarl kept him alive, but when Alcaraz opened up the machine and he exploited it from all angles, sometimes even with lobs kissing the baseline, it was as if the Quebecer’s life support machine had disconnected.

In the semi-finals, Alcaraz will have an appointment with Jannik Sinner, who defeated defending champion Taylor Fritz. It will be time for revenge for the Italian.

Last year, Sinner lost to Alcaraz in the match of the year, in the U.S. Open quarterfinals. The duel lasted 5 hours 15 minutes and ended at 2:50 a.m.

In the other men’s semi-final, the Tour’s player of the hour, Daniil Medvedev, will face Frances Tiafoe.