Florida’s Sofia Kenin became the new face of American women’s tennis on Saturday in Melbourne, defeating former world No. 1 Garbine Muguruza of Spain for her first Grand Slam title at the Australian Open.

The 21-year-old will be the highest-ranked American women at No. 7 when the new WTA rankings are released on Monday as she became the youngest American woman to win a major since Serena Williams.

Known for her fighting style and mental toughness, the American No. 14 seed won the final from a set down, defeating the two-time Grand Slam champion Muguruza 4-6, 6-2, 6-2.

“My dream has officially come true,” Kenin said during the trophy ceremony. “If you have a dream, go for it, because it can come true…I’m so proud of myself, my dad, my team, everyone that has been around me. We’ve all worked hard. We’ve been through tough times. We did it. We fought. I’m just on cloud nine.”

Kenin looked to be fighting nerves in the first set, but in the second she stepped further into the court to take control of rallies.

“I was obviously devastated,” Kenin said of losing the opening set. “I knew I didn’t take my chances. Of course, she played some really good tennis. I’m playing a two-time Grand Slam champion. She’s had so much experience. I knew I needed to somehow forget what happened, just move forward and just keep believing in myself.”

The match turned in the third set as Muguruza served at 2-2, 40-love. Kenin turned the tide with five straight winners to break for a 3-2 lead, and the break shattered the confidence of Muguruza, who would not win another game. The Spaniard double-faulted on game point in her next service game, and did likewise on match point as Kenin dropped her racquet and brought her hands to cover her mouth.

The American, only in her second full year on tour, had never before reached the quarterfinal round of a Grand Slam. Her play in the final included an efficient +5 in winners to enforced errors, converting on five of six break-point opportunities.

Muguruza entered Melbourne at No. 32 on the WTA rankings after a year of struggle in 2019. The 26-year-old former Wimbledon and French Open champion fell to 2-2- in career Grand Slam finals.

“I’m not very happy about my performance,” the Spaniard said afterwards. “I think I had to play better today because she came up with a great level. I think at the important moments I didn’t find my shots. I think she found her shots. I did feel a little bit of a lack of energy after so many matches. Physically, it was a tough battle out there, so it’s just a tough moment.”

Kenin, the 2019 WTA Most Improved Player of the Year award winner, said her confidence took off a year ago with her first WTA title in January.

“[In] 2019, I started off great with a first WTA title in Hobart,” she said. “After that things just took off. I had a great run in Paris. Played my idol, Serena [Williams]. Lost to Ash [Barty] there. Got the revenge here…I knew I had to establish myself to get where I am. All the confidence has come with all the matches that I’ve had, the success I’ve had in 2019.”

For all her steeliness and resolve, Kenin admitted she has had nerves and had “been crying before her matches,” as tweeted by her friend and fellow American player Bethanie Mattek-Sands.

“I knew I needed to somehow try and relax, just try to calm down,” Kenin said of the third set of the final. “I did a great job. I looked a few times to my box. They cheered for me, calmed me down. It just paid off…After that, I was on fire. I was ready to take the beautiful trophy.”