Defending champion Jessica Pegula advanced to the final of the WTA Charleston Open clay-court tournament on Saturday, defeating fourth seed Iva Jovic 6-4, 5-7, 6-3.
American top seed Pegula, who has been taken to three sets in each of her four matches in Charleston this week, finally wrapped up victory in 2hr 35min when Jovic pulled a forehand return wide.
The 32-year-old from New York will face Yuliia Starodubtseva in Sunday's final after the unseeded Ukrainian upset fifth seed Madison Keys in the other semifinal.
World number 89 Starodubtseva, who was initially scheduled to go through qualifying in Charleston before being granted a place in the main draw after a withdrawal, defeated Keys 6-1, 6-4.
World No 5 Pegula will be chasing her second title of the season on Sunday after her victory in Dubai in February.
The American admitted after Saturday's latest three-setter that she has become used to taking the scenic route as she has advanced through the rounds in Charleston.
"When I won the first set today I thought 'Oh man, I have such a great chance to not go to three'. I was like 'Maybe I'll get it done in two today'," Pegula told the Tennis Channel.
"I'd love some straight sets victories – that would be nice. But a win's a win. If I'm gonna win every match for the rest of my life, but it's three sets, I'll take the three sets."
While Pegula will be targeting her second title of the year on Sunday, Starodubtseva will be aiming for the first of her career.
The 26-year-old Ukrainian punished Keys's fragile service game to race through the first set in just 31 minutes, breaking the American four times to win 6-1, before clinching victory with another service break in the 10th game of the second set.
"I did not expect to break her that many times today," Starodubtseva said. "I feel like I did quite well at neutralising her power and just hitting a heavy ball back.
"I can't really described my feelings right now. I may not have expected this outcome in this tournament but hard work pays off."