Katie Boulter overcame a one-set deficit to beat Emma Raducanu 6-7, 6-3, 6-4 in an all-British semifinal at the Nottingham Open on Sunday.
The game resumed on Sunday after bad light had halted play late the day prior following an epic first set that lasted over 80 minutes.
Raducanu claimed that set in a tiebreak but struggled with her serve after the resumption as Boulter, 27, took advantage of several double faults to level the contest.
The deciding set was another tense affair, with Boulter, the British No. 1, breaking in the sixth game only to immediately fail to hold serve herself, the first two of five consecutive breaks as momentum continued to swing back and forth.
The match was eventually won by Boulter on the fifth of those breaks as she came through after three hours and 13 minutes.
Boulter, the defending champion at Nottingham, will take on Karolina Pliskova in the final later on Sunday.
"Honestly I think I'm going to need a little defib out here soon because my heart rate is too high right now," the world No. 30 joked after the match.
"What a match, what an incredible player, I know she [Raducanu] is only going to get better and better and she makes it so tough for you to close it out.
"It has been a really tough week for me; it hasn't been ready to get myself over the line. It's always tough coming back as defending champion -- I've actually never done this before -- so this is a first time for me, but so far it's going pretty good.
"I just need you guys to get me over the line in the next one."
Boulter was included in Team GB's tennis roster for the Paris 2024 Olympics earlier on Sunday, but Raducanu, 21, opted out of the squad as she looks to maintain her fitness and rise up the WTA rankings.
