President Donald Trump waves as he arrives at the US Open tennis men's singles final Sunday, Sept. 7, 2025, in Flushing, N.Y. (AP Photo/Manuel Balce Ceneta)2025-09-07T06:45:03Z NEW YORK (AP) The start of the U.S. Open mens final between No. 1 Jannik Sinner and No. 2 Carlos Alcaraz on Sunday was pushed back by a half-hour because of extra security, and President Donald Trump was greeted with a mix of cheers and boos from early arriving spectators when he waved from an Arthur Ashe Stadium suite.Increased security checks at entrances to the grounds and, separately, to get into the arena building prompted the U.S. Tennis Association to announce that the final would begin at 2:30 p.m. EDT instead of the originally scheduled 2 p.m. EDT to ensure that fans have additional time to get to their seats.Trump is the first sitting president to attend the tournament at Flushing Meadows since Bill Clinton in 2000.Sinner, a 24-year-old from Italy, is trying to become the first repeat mens champion at Flushing Meadows since Roger Federer won five championships in a row there from 2004 through 2008. Hes also bidding for his third Grand Slam title of the season, after the Australian Open and Wimbledon, and fifth of his career.Alcaraz, a 22-year-old from Spain, is seeking his sixth major trophy overall and second of 2025, after the French Open. His first Slam title came in New York in 2022 as a teenager after defeating Sinner in the quarterfinals. Even though both are quite young, theirs is already quite a remarkable rivalry.Sundays showdown represents the first time in tennis history that the same two men played each other in three consecutive Grand Slam finals within a single season. This hard-court matchup follows Alcarazs victory over Sinner erasing a trio of match points on the French Opens red clay in June, and Sinners victory over Alcaraz on Wimbledons grass in July.So this is a tiebreaker of sorts. Plus the winner will be at No. 1 in the rankings on Monday.No matter who comes out on top, this is the eighth consecutive major title and 10th of the past 13 that will end up in the hands of Sinner or Alcaraz. Sundays match is Sinners fifth final in a row at the biggest events in tennis, a run that began with his title at the U.S. Open a year ago. Since the start of that tournament, he has won 33 of 34 matches at the majors. The loss? To Alcaraz at Roland-Garros.Over the last two seasons, Sinner is 1-6 against Alcaraz and 109-4 against everyone else.Alcaraz, meanwhile, has won 36 of 37 contests since May. The loss? To Sinner at the All England Club also Alcarazs first defeat in a Slam final. Alcaraz leads the tour in wins (60) and titles (six) in 2025 and has reached the finals at his past eight tournaments.___Howard Fendrich has been the APs tennis writer since 2002. Find his stories here: https://apnews.com/author/howard-fendrich. More AP tennis: https://apnews.com/hub/tennis HOWARD FENDRICH Fendrich is an Associated Press national writer based in Washington, D.C. He reports on tennis and other sports. twitter mailto