Polina and Veronika Kudermetova both reached the quarterfinals of a Hologic WTA Tour event for the first time after the sisters notched upset wins on Wednesday at the Hana Bank Korea Open. 

Seoul: Scores | Order of Play | Draw

Lucky loser Polina, 21, came from 5-3 down in the second set to oust 2022 champion and No.7 seed Ekaterina Alexandrova 6-2, 7-5. Polina had lost to China's Lu Jia-Jing in the final round of qualifying but has rebounded to post the first Top 50 win of her career and reach the Seoul quarterfinals for the second year in a row.

Former No.9 Veronika, 27, followed by knocking out No.2 seed Liudmila Samsonova 6-4, 6-2 in the last match of the night session. She improved to 5-2 overall against Samsonova, including three consecutive wins in the past 12 months. Having slumped to No.44 -- and suffered a loss from 5-0 up in the third set to Camila Osorio last week in Guadalajara -- the victory, which featured a spectacular passing shot in the second set, marks a much-needed rebound.

"It's really nice feeling because this season, let's say, is not perfect for me," Veronika said afterward.

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The sisters had both reached the second round of a WTA event once previously, at 's-Hertogenbosch 2023. But with Polina's ranking at No.163, they don't often get to compete in the same tournaments. She tries to watch Veronika's matches whenever possible to pick up tips -- "Even when we're on different continents" -- but this week, Polina has been able to take advantage in person.

It started with a practical insider tipoff. After Polina's qualifying loss, Veronika reminded her to sign in as a lucky loser, pointing out that Magdalena Frech would be a likely withdrawal from the main draw owing to the Pole being busy winning the Guadalajara title on Sunday.

With Polina's coach Ravshan Sultanov unable to travel to Seoul owing to complications in applying for a visa from his native Uzbekistan, Veronika's coach and husband Sergey Demekhine was also able to step in instead.

"We're together practising all the time," Polina said. "It was a really good experience for me, because she was No.8 in the world and I'm only going up, up now. All the time I'm learning."

Veronika has long spoken of Polina, a former junior No.4, as one to watch. Her main advice to her little sister -- echoed by Sultanov -- has been to focus on a point-by-point mentality during matches. 

"Focus by point, focus by game," Polina said. "You don't know what it will be so just play your game. Support yourself more in the match, be more positive."

That came in handy as Polina overturned the second-set deficit against Alexandrova, but it's another recent match that she says really underlined the importance of this outlook. Two weeks ago, she found herself trailing Miriam Bulgaru by a set and 5-2 in the Montreux WTA 125 second round. But she stared down a total of seven match points, and emerged a 3-6, 7-5, 6-3 victor.

"That was really good for me," she said. "[Sultanov] was saying, 'Let's go!' and 'Play every point!'"

Veronika seconded Polina's appreciation of the sisters being reunited on tour.

"Our mum is here as well, almost a full family," she said. "Every night we go to dinner together. You don't feel that much stress when your family is close to you."

However, she joked that Polina's success in the tournament wasn't so much an inspiration for her as a realization that she needed to up her own game.

"It’s extra motivation for me, of course!" Veronika said. "This is so bad from my side. Extra motivation to do better than her."

Polina -- whose second-favorite player, after her sister, is Aryna Sabalenka owing to the World No.2's aggressive approach -- will next face either No.3 seed Beatriz Haddad Maia or Ajla Tomljanovic. Veronika is set to meet either Amanda Anisimova or Viktoriya Tomova. If both sisters win those matches, they could meet in the semifinals.

Elsewhere, No.4 seed Diana Shnaider and No.5 seed Marta Kostyuk both eased into the last eight with straight-set wins over qualifiers. Shnaider advanced 6-3, 6-3 past Carol Zhao in 1 hour and 7 minutes, while Kostyuk dismissed Heather Watson 6-2, 6-2 in 1 hour and 15 minutes.

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