The latest episode of a feud more than 10 years in the making will take place next month, as longtime rivals Valentina Shevchenko and Joanna Jedrzejczyk duel for the vacant UFC women’s flyweight championship.

When Shevchenko enters the cage to face the Polish former UFC strawweight champion, it will have a strange sense of familiarity to it.

In what must seem like a past life at this point, Shevchenko and Jedrzejczyk have met on three prior occasions in Muay Thai competition - and three times it was Shevchenko whose hand was raised in victory.

As Valentina’s big sister Antonina told RT Sport, she expects a similar result when the two laser-sighted strikers meet once again at UFC 231, this time under MMA rules.

“Every year since 2006 we have this story - Valentina with Joanna," Antonina said.

“In the World Championship of Muay Thai it was the first time they met in Bangkok. So the next year, 2007, we had the same story, Valentina and Joanna. Valentina wins and Joanna loses.”

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They met again the following year in the finals in South Korea. Valentina once again won a decision - her third straight victory against Jedrzejczyk - though Antonina admits that this was the closest of the three fights between the pair.

Antonina, 34, kicked off her own UFC career on Friday night at The Ultimate Fighter Finale in Las Vegas, where she won all three rounds to defeat South Korea's Ji Yeon Kim via unanimous decision, with her younger sister screaming instructions from her corner throughout the contest.

Like her sister Valentina, Antonina also competes in the UFC flyweight division, which she calls a "very exciting" one.

"A lot of good girls, who didn't have good experience in different weight classes came down and up to 125, and I think it will a good weight category... When Valentina will be the champion!"

READ MORE: Double Barrel: Valentina ‘Bullet’ Shevchenko’s big sister Antonina aiming for UFC glory

She also admitts that, while Jedrzejczyk is very much Valentina's problem at the moment, she would certainly be interested in a future fight with the Polish former strawweight champion further down the line.

“Now, 10 years later, they’re both different fighters. Every time it was Valentina and Joanna, so I never thought about me and Joanna, but if she will fight at 125, yes, why not?" she said.

Joanna was a UFC champion for a long time. She did a great job in that division, in 115. But against Valentina she has no chances!

"It’s Valentina’s division at 125. It’s different power. Joanna already felt this power against Valentina and she will feel it again in this fight. I think they will both go for the finish. There is too much blood, too much history in this fight.

"Because in Muay Thai Joanna (could only) become world champion after Valentina moved to another division. And of course Joanna will be training hard, I expect her (to). Because she always has this ambition of being a champion. And she did great, but against Valentina it will not work."