Vekic will be looking to win her first WTA Tour title in her second final on Sunday against Daniela Hantuchova after coming through 7-6 (7/5) 1-6 6-3 against 2009 tournament winner and 16th seed Magdalena Rybarikova in Birmingham.
"I found a way to win, it wasn't my best day, I didn't play my best tennis but at the end of the day I won the match and I can try to improve my game tomorrow [Sunday]," said the unseeded Vekic on the tournament's official website.
"I was a bit nervous today [Saturday], it is never easy serving for the match but I just have to get the ball in the court somehow. I'm just very excited and I'm not going to really think about my match too much, I'm just going try to relax for a bit and see how it goes tomorrow [Sunday]."
The Croatian was beaten in her maiden final in the Tashkent Open last September, but has impressed this week with wins over seeded pair Urszula Radwanska and Sorana Cirstea en route to Sunday's showpiece.
Indeed, Vekic lost just three games against third seed Cirstea in the quarter-final of the Wimbledon warm-up event and on Saturday responded well after losing her way in the second set against her Slovakian opponent.
In the other semi-final, Hantuchova hit back from a set down to edge out Alison Riske, who had earlier in the day upset fifth seed Sabine Lisicki 7-6 (7/2) 2-6 6-4 in the last-eight clash that was suspended on Friday night at 2-2 in the deciding set due to the inclement weather.
American Liske seemed to show no signs of fatigue by winning the first set against Hantuchova but the Slovakian hit back to triumph 5-7 6-1 6-4 and reach her first singles final since February last year.