Top seed Caroline Wozniacki progressed to an Eastbourne final for the third time in her career after saving a match point in her Nature Valley International last-four contest with Angelique Kerber.
Wozniacki, the tournament's winner in 2009 and a runner-up 12 months ago, had to dig deep to secure a 2-6 7-6 (7/4) 6-4 success at Devonshire Park.
In the final, Wozniacki will face Belarusian Aryna Sabalenka, who reached her third WTA Tour final by overcoming Agnieszka Radwanska 6-3 1-6 6-3.
Wozniacki had lost to Kerber eight times in her career and she came close to a ninth when down 5-6 in the second set, having lost the first when the German secured a double break to reel off five games in a row.
As it was, Wozniacki won that crucial second-set point in a 24-shot rally, came out on top in the second set tie-break before making the only break in the final set.
"That was very tough," Wozniacki admitted in quotes published on the WTA's official website.
"I was down match point and I think I got a little lucky hitting both lines, and then I somehow managed to get through.
"I always have tough matches against Angie, and I knew it wasn't going to be an easy one."
In the other semi-final, 20-year-old Sabalenka won her fifth consecutive three-set match at the tournament to oust 2008 champion Radwanska.
Sabalenka had to do it the hard way too, coming from a break down in the deciding set to book her passage.
In the men's tournament, Mischa Zverev will meet Lukas Lacko after the pair secured straight-sets victories over Mikhail Kukushkin and Marco Cecchinato respectively.
Neither Zverev or Lacko have ever won an ATP Tour title before.