Alcaraz, 19, showed none of the weariness he was expected to - having gone the distance in the last three rounds. Instead, the Spaniard - playing his first Major final - fended off break points before breaking for 2-1 in the first set. Soon, Alcaraz served out the opener to draw first blood.
However, Ruud came roaring back into the contest, conceding only two games as he leveled proceedings in the second set. Alcaraz then squandered a break lead and needed to save two set points before taking the all-important two-sets-to-one lead by winning the ensuing tiebreak.
The Spaniard was the better player in the fourth - breaking decisively - before converting his second Championship point to sink to the turf in unbridled joy.
With his win, Alcaraz became the first US Open winner in six years to save a match point (against Jannik Sinner in the quarterfinals) along the way. The Spaniard also created a few other records on the night. On that note, here's a look at five of them:
#1 Carlos Alcaraz is the first player in three decades to win a Major after playing 5 sets in 4R, QF and SF
Carlos Alcaraz has emerged as the new marathon man of men's tennis. The Spaniard belied his tender years to see off Marin Cilic, Jannik Sinner and Frances Tiafoe in five sets to make his first Major final.
With his win over Ruud on Sunday, Alcaraz became the first player in three decades - since Stefan Edberg at the 1992 US Open - to win a Major after going the distance in the three rounds before the final.
Alcaraz is now 8-1 in five-set matches - with his only loss coming against Matteo Berrettini at the Australian Open earlier this year in the third round. Five of the Spaniard's five-set wins have come at Flushing Meadows.
#2 First player in Open Era to win the US Open in his second appearance
Carlos Alcaraz reached the quarterfinals last year on his US Open debut, losing to Felix-Auger Aliassime. A year later, Alcaraz came close to losing in the last eight once again, but saved a match point on his opponent's serve to move to the next round. Two more rounds later, the Spaniard beat Ruud to win his first Major title.
In the process, Alcaraz has become the first player in the Open Era to win the US Open in only his second appearance in New York.
Pancho Gonzalez also won the US Open in his second appearance in 1948, but that triumph was in the pre-Open Era.
#3 Youngest Grand Slam winner in nearly two decades
Carlos Alcaraz has had a banner year in 2022, evoking comparisons with his illustrious compatriot Rafael Nadal. After becoming the youngest two-time Masters 1000 winner and top-five player in nearly two decades, Alcaraz is now the youngest Major winner since Nadal triumphed at Roland Garros in 2005.
Alcaraz is now the second Spaniard in three years to win at Flushing Meadows after Nadal won his fourth title in New York in 2019.
#4 Youngest US Open winner in more than 3 decades
Carlos Alcaraz is now the youngest US Open winner in more than three decades. The 19-year-old has also become only the second teenager to win the last Grand Slam of the year.
Pete Sampras is the only other teenager to triumph at Flushing Meadows, going all the way in 1990. The American remains the youngest US Open winner in the Open Era.
Sampras would go on to win 13 more Majors, including four more in New York, something Alcaraz would love to emulate or even surpass.
#5 First teenager to become World No. 1
Carlos Alcaraz and Casper Ruud came into a winner-take-all clash in the US Open final - with a first Major title and the World No. 1 ranking on the line. Eventually, both went Alcaraz's way, with the second accomplishment making the Spaniard the first teenager to become the ATP World No. 1 since rankings came into being in 1973.
Alcaraz has lowered the previous record of Lleyton Hewitt (20 years, 9 months) by nearly 1.5 years.
Also Checkout:- US Open 2022 Results