Sinner has struggled in the past year, and not just on the tennis court. After a doping case, from which he eventually emerged with only a three-month ban, he has humbly made a comeback and has won much of the crowd back to his side, thanks to his gentlemanly demeanour.
It was the final at Roland Garros in particular that foreshadowed what was to come. Sinner, together with Alcaraz, put on an impressive five-set battle, but one in which there was also plenty of mutual respect. The Italian lost in Paris to his Spanish rival for the fifth time in a row! But in the end, he admitted that this moment spurred him on to even greater diligence.
"It wasn't easy, but I always try to be honest with myself. But I think when you lose a Grand Slam final in that way, it's much better than being swept away.
"So I told myself after Roland Garros that it's not the time to be depressed. I put my strength into every practice because I felt I could play very well. Another Grand Slam was coming up..." he recounted.
Although he unexpectedly lost to Alexander Bublik in Halle in his only tune-up before Wimbledon, he breezed the first week at the All England Club with comfortable wins against compatriot Luca Nardi, Aleksandar Vukic and Pedro Martinez.
Key moments
Fourth round: Sinner vs Dimitrov (3-6, 5-7, 2-2)
Up until the fourth round, Sinner's matches looked almost boring. The world's best lost only 17 games in the first three rounds, equalling Jan Kodes' record from 1972. But the Italian was stunned by 34-year-old veteran Grigor Dimitrov.
Dimitrov going into a 2-0 lead was no accident at all, the Bulgarian played confidently and energetically and literally destroyed favoured Sinner (the ratio of points won was 79-64 to Dimitrov).
But then came the twist. The Bulgarian tore his pectoral muscle on his own serve and had to abandon the match. "I don't take this as a victory at all," Sinner admitted in his on-court speech. He literally fell from the sky to reach the quarterfinals. As it turned out, he needed just six wins instead of seven to triumph.
Semi-final: Sinner vs Djokovic (6-3, 6-3, 6-4)
After the draw of the tournament, Sinner's path to the final looked much more complicated. After all, his half of the bracket included the iconic Novak Djokovic, who had last missed a Wimbledon final in 2017. But there was no big battle between the two this time.
It was obvious that the Serbian champion was not in good shape and was clearly limited by some injury. As a result, the Italian wasn't pushed in this semi-final. He solved the complications caused by the loss of serve in the third set by winning five games in a row (a turnaround from 0-3 to 5-3) and booked his spot in the Wimbledon final for the first time in his career.
The final: Sinner vs Alcaraz (4-6, 6-4, 6-4, 6-4)
Alcaraz's 15 aces counted for little, as a totally focused Sinner was dialled in to avenge his loss in Paris. The Italian didn't lose his nerve and dominated from the second set onward. On his own serve after the first set, he allowed the Spaniard only three break points, all of which he saved.
Sinner showed that even on grass, his game has great variety when he is in the ideal frame of mind. He played a lot of balls from the baseline and was also successful at the net, where he capitalised on 30 out of 40 shots.
Key numbers
23 years and 318 days - Sinner may not be the youngest Grand Slam winner, but he is the second youngest player in the Open era to reach the men's singles final at all four Grand Slam tournaments. Only Jim Courier had done it before (and by only 10 days) in 1993.
54 and 12,000 - Even with a controversial doping case, he missed several months, yet managed to stay at the top of the ATP rankings and reasserted his lead at Wimbledon. Sinner has been the best player in the world for more than a year now, and after his triumph at the London Grand Slam, he also surpassed the feat of Djokovic, who managed "only" 53 weeks in a row during his first stint as world number one.
He has also now become only the fifth world number one to break the 12,000-point mark. Before him, only Rafael Nadal, Roger Federer, Djokovic and Andy Murray have done it.
63% - What is Sinner's strength? At Wimbledon, he had fantastic numbers in his second service game success rate. He successfully completed 130 out of 205 second-serve points, with only Tomas Machac and Cristian Garin doing better in terms of percentage, but they only played two matches.
Sinner looks like a tennis machine. At his best, he's uncompromising. And even though Alcaraz looks more technically gifted, the Italian can outplay him with his relentlessness. There's already been talk of his versatility; he's conquered the trophy on grass in addition to the hard grand slams in Australia and the US Open.
He is still missing out on a clay triumph at the French Open, though, where he has also reached the final. But perhaps far more resonant is that rivalry with Alcaraz, which Wimbledon predicted the year before on the official poster, which many criticised as disrespectful to the 'Big Three'.
Today, however, Sinner belongs on the poster. And he adds that he needs Alcaraz for his growth. "Rivalry with Carlos? That's the other motivation. But I don't think I'm at my best yet: I'm 23, I hope I can continue to improve."