Carlos Alcaraz has used his combination of moxie and maturity to beat Casper Ruud 6-4, 2-6, 7-6 (7/1), 6-3 in the US Open final to earn his first grand slam title at age 19 and become the youngest man to be ranked world number one.

Appearing in just his eighth major tournament and second at Flushing Meadows, Alcaraz has already attracted plenty of attention as someone considered the next big thing in men's tennis.

He was serenaded by choruses of "Olé, Olé, Olé! Carlos!" that reverberated off the closed roof at Arthur Ashe Stadium — and Alcaraz often motioned to the supportive spectators to get louder.

He only briefly showed signs of fatigue from having to get through three consecutive five-setters to reach the title match, something no one had done in New York in 30 years.

Alcaraz dropped the second set and faced a pair of set points while down 6-5 in the third. But he erased each of those point-from-the-set opportunities for Ruud with the sorts of quick-reflex, soft-hand volleys he repeatedly displayed.

And with help from a series of shanked shots by a tight-looking Ruud in the ensuing tiebreaker, Alcaraz surged to the end of that set.

One break in the fourth was all it took for Alcaraz to seal the victory in the only grand slam final between two players seeking both a first major championship and the top spot in the ATP's computerised rankings, which date to 1973.

Ruud, the 23-year-old from Norway, is now 0-2 in slam finals. He was the runner-up to Rafael Nadal at the French Open in June.

Ruud stood way back near the wall to return serve, but also during the course of points, much more so than Alcaraz, who attacked when he could.

Alcaraz went after Ruud's weaker side, the backhand, and found success that way, especially while serving.

Alcaraz certainly seems to be a rare talent, possessing an enviable all-court game, a blend of groundstroke power with a willingness to push forward and close points with his volleying ability. He won 34 of 45 points when he went to the net.

He is a threat while serving — he delivered 14 aces at up to 128mph on Sunday -- and returning, earning 11 break points, converting three.

When one last service winner glanced off Ruud's frame, Alcaraz dropped to his back on the court, then rolled over onto his stomach, covering his face with his hands.

Then he went into the stands for hugs with his team, including coach Juan Carlos Ferrero, a former number one himself who won the French Open in 2003 and reached the final of that year's US Open.

You only get to number one for the first time once. You only win a first grand slam title once. But many folks expect Alcaraz to be celebrating these sorts of feats for years to come.