Daria Kasatkina needed minimal effort to secure her second WTA title of the season on Sunday when fellow Russian Margarita Gasparyan quit while trailing 6-3, 2-1 with back problems in St Petersburg.
The No. 61 winner also picked up a trophy last month at a pre-Australian Open tournament in Melbourne, making her the first this season to pocket a second honour.
No. 126 Gasparyan was unable to continue, with her retirement sending Kasatkina to a 15-4 record this season.
Kastakina, winner of the 30th all-Russian final since 2000 did it tough this week, coming from a set down in three previous matches to advance to the trophy match.
Her defeated opponents included Aliaksandra Sasnovich, second seed Veronika Kudermetova and No.4 double Grand Slam winner Svetlana Kuznetsova.
Kasatkina also won the Moscow titles three years ago, a win which earned her a breakthrough Top 10 ranking; her career total stands at four after also winning Charleston in 2017.
The 21-year-old champion who is fighting out of a 2019 slump is expected to crack the Top 50 again on Monday.
Wild card entry Gasparyan needed a medical time out while trailing 4-1 and was never able to mount an attack.
She quit after losing a 40-0 lead in the second set in what became a final game marred by a pair of double-faults.
Main photo:- Daria Kasatkina becomes first to claim a second WTA title in 2021 with St. Petersburg trophy – by WTA Tennis.com