Meanwhile, Belgian Ruben Bemelmans faces big-hitting American Steve Johnson in the men’s singles final.
Baltacha battled her way past Czech fifth seed Barbora Zahlavova Strycova 6-4 6-4 to advance to the last four of any competition for the first time since returning from foot surgery before she was handed a wildcard into the main draw of the Aegon International at Eastbourne.
The Team GB Fed Cup star said the quarter-final win against the world number 127 was a significant step in her comeback, having struggled with the rigours of the game in recent weeks.
“I feel like I’m on cloud nine,” Baltacha said. “As the days are going on I’m feeling more and more confident, and I really felt in control, I felt I could slow everything down today.
“I knew what I was doing out there, what I had to do and that I could deliver.
“I’m not saying that I feel that I can do what I want - that I was brilliant and that I can take anyone out - but I do feel that I can deliver my game, the tactics I want to deliver and execute.
“This was a massive step for me. All these matches back-to-back have been a real test.
“At this point, the fourth match, in Saint Gaudens last month I was a bit tired mentally, whereas today I’m not at all fatigued. What that means is that I’m really making progress.”
Baltacha, a former Aegon Nottingham Challenge champion, was delighted to again subdue a tenacious opponent and overcome the elements after her second round meeting with compatriot Emily Webley-Smith was also badly affected by rain on Thursday.
Having returned to action after a four hour delay on Friday leading 2-1, Baltacha broke early and was serving for the set at 5-3 when she was broken back.
She, however, broke straight back to heap pressure on the Czech before going on a four game run to take command of the second set.
But Zahlavova Strycova clawed her way back, denying Baltacha victory as she twice served for the match.
But the Scot replied in devastating style, breaking the right-hander to advance to the semi-final.
“It was brilliant that I was able to fight back when I needed to, it is what I need right now,” Baltacha said.
“In the last few weeks a lot of things have happened - there are things that are thrown at you which you are not familiar with after being out for so long, but you need to bank again.
“That third and fourth day at Saint Gaudens, after my body hadn’t done that for nine months, was a struggle and I lost it because I was mentally fatigued after back-to-back wins.
“After I experienced that, I knew that if I faced the same situation, like I did today, I would react differently and I would be both mentally and physically ready for it.”
Baltacha joins the likes of world number 14 Samantha Stosur as a wildcard at the WTA Tour event in Eastbourne, which starts on June 15 at Devonshire Park.
“The Aegon International is one of my favourite tournaments, I always look forward to playing there,” she said.
“It's an honour to have been given the wild card and it's perfect because I'm still in at Nottingham so I couldn't have played qualifying at Eastbourne.”
Elsewhere, Miki Miyamura says she has nothing to lose against seventh seed Tadeja Majeric in their women’s singles semi-final.
The Japanese qualifier swept through her first ITF Pro Circuit quarter-final at the Nottingham Tennis Centre, beating Canadian Stephanie Dubois 6-4 6-4.
Miyamura arrived in Nottingham for the Aegon Trophy last week solely focused on trying to edge her way into doubles qualifying for Wimbledon with playing partner Varatchaya Wongteanchai.
It all turned to disaster as they crashed out in the first round.
But this week has seen Miyamura shine in a remarkable run through qualifying, past France’s Julie Coin in the opening round of the main draw, over eighth seed Julia Glushko in the second round before powering past Dubios, who is ranked 263 places higher in the world.
“Maybe there are many people who cannot believe that I’m in the semis – I can’t believe it myself,” Miyamura said.
“I have no pressure on me now that I’m here - I think I have been very lucky."
In the men’s decider, Johnson is relishing his second ATP Challenger final appearance after winning his maiden title at Aptos, USA, last year. The 23-year-old beat Somdev Devvarman in straight sets to reach his first decider on grass.
“It is a good omen, I’m one from one so far in finals so hopefully I can keep the streak alive,” he said.
“Somdev is a great player, he’s fought back a few times to progress in this tournament – he makes good adjustments and I respect him a ton.”
Belgian Bemelmans came back to beat South Africa's Rik De Voest in three sets 5-7 7-6(5) 7-6(5) in two hours 47 minutes to book his place in the final.
Aegon Nottingham Challenge results – Friday 14 June
Men’s singles – semi-finals
R Bemelmens (BEL) d R De Voest (RSA) 5-7 7-6(5) 7-6(5)
S Johnson (USA) d S Devvarman (IND) 6-3 6-4
Women’s singles – Quarter-finals
E Baltacha (GBR) d  B Zahlavova Strycova (CZE) 6-4 6-4
 T Majeric (SLO) d  P Martic (CRO) 1-6 6-0 7-5
[Q] M Miyamura (JPN) d S Dubois (CAN) 6-4 6-4
 N Burnett (ITA) d M Brengle (USA) 6-4 2-6 6-4
- Sports & Recreation
- Aegon International
- Barbora Zahlavova Strycova