SAINT PETERSBURG: Daria Kasatkina captured her second WTA title of the season as Margarita Gasparyan retired with a back injury during the second set of Sunday’s final in Saint Petersburg. Former world number 10 Kasatkina led 6-3, 2-1 in an all-Russian final when Gasparyan was forced to quit, handing her opponent a fourth career title. Kasatkina, 23, also won last month’s Phillip Island Trophy in Melbourne, her first tournament victory since her 2018 triumph in Moscow. Gasparyan, ranked 126th and playing on a wildcard, took a medical time out during the first set but stopped after double-faulting twice and dropping serve in the third game of the second set. Kasatkina endured a difficult 2019 and slumped to 75th last year but will climb back into the top 50 Monday after becoming the first player to win two WTA events in 2021.