(Reuters) - Angelique Kerber defeated fellow German Andrea Petkovic in straight sets on Saturday to reach the final of the Family Circle Cup where she will face American Madison Keys.
Defending champion and third seed Petkovic went into the semi-final having won her previous 11 matches in Charleston, South Carolina and the last three clashes with Kerber.
But the paper form counted for little once the action began with the left-hander breaking in the second game and taking the first set 6-4.
Kerber, the fifth seed, built a 5-1 lead in the second and although Petkovic won the next three games, Kerber kept her cool, serving out to love to secure a 6-4 6-4 victory.
Sunday's final will be Kerber's first on the WTA Tour since her loss to Serena Williams at Stanford last year.
Keys ended the hopes of Czech Lucie Hradecka, who had enjoyed impressive wins over number eight seed Caroline Garcia and fourth-seeded Italian Sara Errani in the previous rounds.
The 20-year-old American's serve was strong. She saved the only break point she faced as she won 6-1 6-4 in 67 minutes.
"It is always great when you can get off to a good start and I just kept going with it," said Keys.
She is expected to rise to a career high number 17 in next week's world rankings and even higher if she can pull off a surprise against Kerber.
The pair met in Eastbourne last year in Keys' only other appearance in a WTA final, which she won.