US Open: Bianca Andreescu in tears after defeating Serena Williams

Andreescu's victory Saturday prevented Williams from claiming what would have been her record-tying 24th major singles championship.

New York: Canadian teenager Bianca Andreescu upset Serena Williams 6-3, 7-5 in the U.S. Open women's singles final for her first Grand Slam title.

Andreescu's victory Saturday prevented Williams from claiming what would have been her record-tying 24th major singles championship.

"This wasn't the only time I have visualized playing in the finals actually against Serena Williams. It's so crazy, man. I've been dreaming of this moment for the longest time. Like I said after I won the Orange Bowl, a couple of months after, I really believed that I could be at this stage. Since then, honestly, I've been visualizing it almost every single day. For it to become a reality is just so crazy. I guess these visualizations really, really work," Bianca said.

This is the second year in a row that Williams has lost in the U.S. Open final.

"I'm sure I'm not the only person that's looked up to her. She's an inspiration to many, many people, not only athletes. What she's done off the court too. She's truly a champion. Above all, she's very kind-hearted. She came up to me in the locker room, she said some really nice things which I'll cherish for a really, really long time. But, yeah, I've really strived to be like her. Who knows? Maybe I can be even better," Bianca said while praising Williams.

She has now been the runner-up at four of the seven majors she has entered since returning to the tour after having a baby two years ago.