Kenin's rise and run leads her to the Melbourne final

With seven U.S. women in the WTA Top 30—plus Venus Williams and Coco Gauff unseeded and looming—it was anyone's guess two weeks ago which of them might make a deep run at the Australian Open.

Serena Williams is threat to win any tournament she plays in. Sloane Stephens and Madison Keys have made Slam semis or better a combined seven times. Danielle Collins and Alison Riske have each been having a mid-career surge. And Amanda Anisimova reached the fourth round last year.

Those who watched last season closely, though, likely had an eye on the player with two names: Sofia "Sonya" Kenin, the 5'7" 21-year-old voted the WTA's 2019 Most Improved Player of the Year.

Born in Moscow, Kenin quickly made a name for herself after immigrating to the United States, where she was noticed by legendary coach Rick Macci when she was 5.

Even in childhood, her talent was as evident to herself as it was to others, and her belief in herself was as unwavering as it is now: Watch her at age 7 explain how she could return Andy Roddick's serve:

After winning the Orange Bowl and making the final of the girls' US Open at 16, Kenin won four ITF tournaments from 2016 to 2018, entering the top 50 and laying the groundwork for main-tour success.

Then came the life-changing 2019, in which she won three WTA singles titles, in Hobart, Mallorca and Guangzhou. Kenin additionally took two doubles crowns and made the singles final in Acapulco.

But maybe most notably, she grabbed the world's attention at Roland Garros, where she ended Serena's run in the third round, 6-2, 7-5, and took a set off eventual champion Ashleigh Barty.

Now ranked No. 15, Kenin took another shot at Barty, this time in the Australian Open semifinals. Taking on the world No. 1 at Barty's home major was a different task entirely, one required the confidence of a seven-year-old who thought she can return Roddick's serve, or that of a 20-year-old who has what it takes to defeat Serena Williams in a Slam.

Kenin rose to the challenge, 7-6 (6), 7-5 to reach her first Grand Slam final. Over six rounds, Kenin has won 12 sets and dropped only one (to Gauff), though no seeded player had been in her way until Barty.

"I've worked so hard," Kenin said. "I've put all the efforts into my practices, into my fitness. All the efforts I've been doing, it's got me here. It's just paying off and it's like a dream come true for me."

And about that Roddick video?

"I think everyone knows about it," she said. "By the way, he tweeted something about me. He said congratulations and stuff, so... Thank you, Andy."

She'll play Garbine Muguruza for the title on Saturday.