Madison Keys was assured of breaking into the top 10 in the women's rankings for the first time after beating Carla Suarez Navarro on Saturday to advance to the Aegon Classic final.

Keys, a 21-year-old American whose ferocious hitting could make her a major force on grass, won 3-6, 6-3, 7-6 (3) against the 15th-ranked Spaniard. She'll rise from No. 16 into the top 10 when the new rankings are released on Monday.

"I heard about the top 10 ranking from my coach but tried to pretend I didn't know about it," she said.

Keys becomes the first American woman to make her top-10 debut since Serena Williams in 1999.

It will also be the first time since 2005 that the U.S. has had three women in the top 10. Serena is currently ranked No. 1 and her sister Venus Williams is No. 9.

Against Suarez Navarro, the seventh-seeded Keys showed intermittent brilliance mixed with unforced errors in her fiercely uncompromising game, which Keys described as "a balancing act between going for the right shot at the right time and being more consistent."

Keys was outplayed by the sixth-seeded Spaniard in the first set, but then took charge of the second and took a 4-2 lead in the third. Suarez Navarro came back to force a tiebreaker, but Keys dominated the decider by punishing the Spaniard's second serve.

Keys faces 30th-ranked Barbora Strycova in the final after the Czech beat CoCo Vandeweghe of the United States 2-6, 6-4, 6-3 to make her second final in the tournament in three years