Erika Andreeva defeated her higher-ranked younger sister Mirra in the first professional meeting between the two talented siblings to reach the last 16 at the Wuhan Open.
The Russian pair became the first sisters to play each other in a WTA main draw match since Serena Williams defeated older sister Venus at the Top Seed Open in Kentucky in August 2020.
Erika, 20, claimed a 6-3 6-1 win over 17-year-old Mirra and will now play Italian world number six Jasmine Paolini for a quarter-final place.
Mirra, the 16th seed, said prior to the meeting that she and Erika had agreed to split the prize money from the second round contest, whatever the outcome.
French Open semi-finalist Mirra became the youngest player to be ranked in the top 20 since 2006 last week, courtesy of her run to the quarter-finals at the China Open in Beijing.
But, despite being favourite against Erika, who is ranked 70th in the world, Mirra correctly predicted facing her sister would be “a nightmare”.
Erika is yet to progress beyond the second round in five Grand Slam appearances but, a lucky loser entry in the main draw in Wuhan, she rose to the occasion against her younger sibling.
Already apprehensive about the “stressful” prospect of facing an opponent who knows her game inside out, Mirra claimed the first break of serve and led 3-1.
But Erika responded emphatically by clinching three successive breaks amid a five-game streak to take the opening set.
Erika, a junior French Open runner-up in 2021, extended that unanswered run of games to eight as she took charge with a 3-0 lead in the second set, before earning another break on her way to completing a commanding victory with her third match point.