Casper Ruud sportsmanship hailed after 'classy' act in US Open final

Casper Ruud has been praised across the tennis world after a classy moment in his US Open final defeat to Carlos Alcaraz.

The Spanish teen cemented his status as the next big thing in men's tennis courtesy of a 6-4 2-6 7-6 (7/1) 6-3 victory against the Norwegian.

With a maiden grand slam title and World No.1 up for grabs, the stakes were understandably high for both players at Flushing Meadows on Sunday (Monday AEST).

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Alcaraz struck the first telling blow after taking the first set 6-4, however it came after a helping hand from his Norwegian opponent.

Trailing 4-3, Ruud told the chair umpire that a ball hit by Alcaraz on the opening point of the eighth game had bounced twice on his side of the court before he hit it.

Alcaraz motioned to chair umpire Nico Helwerth for an explanation, with the Spaniard looking confused about what had just transpired.

Ruud then approached the chair and confirmed that the ball bounced twice, prompting a loud cheer from the crowd inside Arthur Ashe stadium.

Alcaraz also gave his opponent a thumbs-up and clapped his hand onto his racket to join the crowd in applause.

Viewers were also thoroughly impressed by Ruud's incredible act of sportsmanship at such an intense moment in the grand slam tournament.

Carlos Alcaraz jumps out to early advantage

Having dropped the opening set, the fifth-seeded Ruud broke Alcatraz's serve twice in the second stanza, before eventually taking it out 6-2.

Ruud had set point chances in the third set but Alcaraz refused to be rattled as the young Spaniard dug deep to force it into a tiebreak.

The 19-year-old stepped it up when it mattered, grabbing a number of mini breaks before jumping out to a 6-1 lead.

Alcaraz took the third set after a wild forehand from Ruud sailed way over the baseline.

The 19-year-old grabbed a crucial break in the sixth game of the fourth set to go up 4-2.

The Spaniard then came from 0-30 down to once again turn the screws on Ruud and move within one game of the claiming the title.

Ruud held serve to force Alcaraz into serving for the match and the result seemed a formality when the Spaniard went 30-0 up.

The 19-year-old had a couple of nervy moments as Ruud got back to 40-30, before Alcaraz sealed his maiden grand slam title with an ace.

The win means Alcaraz becomes the youngest World No.1 in history, breaking the mark set by Aussie Lleyton Hewitt, who was 20 when he became the world's top ranked player in 2001.

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