In what could be considered a potential changing of the guard, 20-year-old Naomi Osaka captured her first Grand Slam, holding off 23-time Grand Slam champion Serena Williams on Saturday in the U.S Open final at Flushing Meadows, New York, 6-2 6-4.

Osaka, who was born in Osaka, Japan, to a Japanese mother and a Haitian father, became the first Japanese player to win a Grand Slam. After the win, she went to the stands to hug her mother, who was in tears. 

Osaka slammed an ace on match point. She then dropped the lid of her visor as she approached the net to hug her idol.

Osaka powered through the 79-minute match with several forehand winners and seemed to pounce on a somewhat uninspired effort from Williams, who made some uncharacteristic and crucial unforced errors.

The 36-year-old Williams dropped five straight games in the first set, while Osaka benefited from a strong serve and an effective baseline game. Osaka finished with 15 winners and converted four out of five break points.

Many tennis experts believe Osaka, who is currently ranked No. 19, is on her way to becoming one of the top players in tennis. After the U.S. Open win, she will move into the top 10.

The deepest Osaka had ever previously advanced in a Grand Slam was the fourth round of the 2018 Australian Open.

The match did not lack controversy. Williams became frustrated with chair umpire Carlos Ramos in the second set after being issued a warning for mid-match coaching from Patrick Mouratoglou.

During the second game of the second set, Williams approached Ramos about the mid-match coaching warning.

"We don't have any code and I know you don't know that and I understand why you may have thought that was coaching," Williams could be heard telling Ramos. "But I'm telling you it's not. I don't cheat to win. I'd rather lose. I'm just letting you know."

Williams later became distraught over a code violation for racquet abuse after losing the fifth game of the second set, which cost her a point as a second offense.

Williams approached Ramos to complain about losing the point because of the earlier mid-match coaching offense. 

"You owe me an apology," Williams could be heard telling Ramos. "I have never cheated in my life."

After Osaka took the lead 4-3 in the second set, Williams returned to arguing with Ramos on the bench. Williams could be heard telling Ramos that he attacked her character in the mid-match coaching violation. 

She yelled to Ramos that he owed her an apology and called him a "liar" and a "thief" for taking a point away from her and demanded an apology. Ramos then issued a game penalty to Williams for verbal abuse, which lifted Osaka to a 5-3 lead in the second set. 

Williams would then call for a separate official, Brian Earley, to intercede. She argued that men say much worse than the comments she directed at Ramos and that it wasn't fair for the comments to cost her a game. 

After the match, Williams did not shake hands with Ramos and pointed at him.