Top seed Holger Rune fought hard to overcome Michael Mmoh in Montpellier, defeating the American 7-6(6), 6-4 after two hours and two minutes.
Rune would dedicate the victory to his sister Alma on her birthday.
He said that he felt he had to win to give his sister the best possible birthday.
Rune’s victory in the first-set tie-break at 5/6 was crucial because he erased Mmoh’s opportunity with a powerful serve that the World No 133 was unable to return.
In the second set, Rune maintained his momentum and won 16 of his 18 first-serve points, moving him into his second semi-final of the season after his run to the Brisbane final.
Rune’s 100th career victory at ATP Tour level came in the second round when the Dane overcame Pablo Llamas Ruiz.
After winning in the quarter-finals on Friday, there was more cause for celebration for Rune and family.
Rune, who will next face fourth seed Borna Coric, said: “When I got the break in the second set, I was thinking, ‘I need to get the win because today is my sister’s [Alma] birthday.
“I was like, ‘Okay, I’m going to give a great gift by winning a match.”
Also on Friday, Coric did not waste any time in defeating Italian Flavio Cobolli 6-3, 6-4. Upon his return, the Croatian displayed a strong game to guarantee his place in the last four and secure his first-ever matchup with Rune.
Three-time tour-level champion Coric is hoping to snap a four-match losing streak in semifinal matches.
If he makes it to the championship match, it will be his first since his magical run to the title in Cincinnati in 2022.
At the ATP 250 indoor hard tournament in France, Alexander Bublik, the winner of Montpellier in 2022, defeated newly-minted countryman Alexander Shevchenko 4-6, 6-3, 6-4 in a match that featured the Kazakhstan top two.
“He is an upcoming player. He has beaten a lot of top players already. I was putting every effort in and I got lucky at the end,” Bublik said. “I didn’t serve any double faults on the break points and I am happy with the win.”
Canada’s Felix Auger-Aliassime got his return game working even if his serve lagged behind a bit.
“To get three breaks in the first set means I was returning really well and then it was just adding the serve to that,” Auger-Aliassime said. “Then being a bit more consistent, a bit more patient and disciplined. I felt like I was playing really good.”