Azarenka was unseeded but hardly a tennis outsider. She was No. 1 for 51 weeks in 2012 and 2013 and won two Australian Open singles titles before Williams reasserted herself at the top of the women’s game, and Azarenka dropped back.
She had injuries, painful breakups with boyfriends and coaches and, most traumatically, a lengthy and bitter custody dispute over her now 3-year-old son, Leo, who stayed with Azarenka and her mother and team at a private home she rented near the U.S.T.A. Billie Jean King National Tennis Center for the tournament.
She would have been the first mother to win a Grand Slam singles title since Kim Clijsters won the Australian Open in 2011. As Azarenka dominated the opening set, hitting nearly every first serve in play and controlling the rallies, it appeared she might win in a hurry. Osaka threw her racket at one stage in frustration as her unforced errors piled up.
“I just thought it would be very embarrassing to lose this in under an hour,” Osaka said, explaining that she told herself to “stop having a really bad attitude.”
Her mood and game improved dramatically as the final progressed, while Azarenka failed to sustain her level of play. After losing the second set and falling behind 1-4 in the third, Azarenka made one more surge, battling through a five-deuce game to hold serve and then breaking Osaka’s serve in the next game to close the gap to 3-4.
But at 30-30 on Azarenka’s serve in the next game, the match turned for good as Osaka won a high-velocity rally to get a break point and then converted it as Azarenka lined up a forehand, went for an inside-out winner and missed just wide.
Osaka, who has yet to lose a major final, then closed out the victory by holding serve as Azarenka’s last shot, a backhand, struck the net. Osaka tapped rackets with Azarenka at the net — another sign of these changed times — and then lay on her back on the court and took a moment to savor the moment.