The top two seeds will contest the Birmingham Classic final on Sunday after Jelena Ostapenko and Barbora Krejcikova secured their places.
Czech top seed Krejcikova, 27, breezed past China's Zhu Lin 6-3 6-2.
Krejcikova's run to the final of the pre-Wimbledon grass-court event will lift her back into the world's top 10.
Later on Saturday, second seed Ostapenko came from behind to beat Russian Anastasia Potapova 5-7 6-2 6-4 and reach a third grass-court final.
Latvian Ostapenko needed three sets to secure victory for the fourth time this week, with her run to the final including a gruelling win over seven-time Grand Slam champion Venus Williams in the previous round.
Potapova, featuring in her first grass-court semi-final, needed six set points to secure the opener before Ostapenko swiftly went a double break up in the second set and secured a deciding set with a stunning forehand down the line.
It was at 3-3 in the third set where the 2017 French Open champion earned a crucial break, hitting four remarkable return winners before sealing the match at the first time of asking when Potapova thrashed her return into the net.
"It was a difficult match - I don't know how I did it, every match has been tough. It's never easy and it's important to win these kind of matches when you're not playing your best," Ostapenko said.
"It's great to play in a final before Wimbledon and get some confidence."
Earlier, Krejcikova brushed aside world number 39 Zhu in a dominant performance.
The 2021 French Open champion has not dropped a set all week in Birmingham and the win will move her back inside the world's top 10 for the first time since May 2022 when the next rankings are published on Monday.
"Being in the top 10 is a goal that you have as a kid. It's really nice to be back but it's just numbers so I want to keep going," Krejcikova said.
The Czech claimed her maiden Grand Slam singles title in 2021 but missed a chunk of last season with an elbow injury and dropped down the rankings.
"It's always tricky on grass," she said. "It's up and down and you have to focus on every ball. I was choosing my shots well and my serve was working - I played well."
Sunday's final is at 14:00 BST and you can watch it live on the BBC Sport website and app and BBC iPlayer.