Wickmayer will break into the top 60 with a win on Sunday
Belgium's Yanina Wickmayer beat American Bethanie Mattek in straight sets to book her place in the final of the DFS Classic in Birmingham.
The 18-year-old will meet Kateryna Bondarenko in her first WTA Tour final as she crowned a remarkable tournament debut with a 7-5 7-6 (7-2) victory.
Bondarenko beat Marina Erakovic 6-3 6-2 to confirm her place in Sunday's final.
"It's my first final and I'm really excited," said Wickmayer. "I'm going to go out there and have some fun."
The Belgian teenager, who knocked out Britain's Melanie South in the quarter-finals, has risen more than 300 places in the world rankings in the last 12 months and will break in to the top 60 with victory over her Ukrainian opponent on Sunday.
She raced into a 5-1 lead, but Mattek rallied to level at 5-5 before Wickmayer regained her composure to take the first set.
The 23-year-old American raced into a 4-1 second set lead, but the Belgian reeled off three games in a row to level the set.
Mattek forced a tie-break as her opponent served to win the match but after slipping 4-0 behind she could not recover and Wickmayer secured her first ever final appearance.
"It's been an opportunity this week to open my eyes and I've learned a lot," added Wickmayer. "It's been a really good experience."
It will also be a first tour final for 12th seed Bondarenko, who lost to the Belgian in the Fed Cup earlier this year.