Sandra Zaniewska: The Polish Coach Behind Marta Kostyuk's Wimbledon Quarter-Final Run

Ukrainian tennis player Marta Kostyuk has reached the Wimbledon quarter-finals, bettering her previous best result in London. Her improved performances are credited to Polish coach Sandra Zaniewska, who has been working with the Kyiv-born player. Kostyuk carried strong form into Wimbledon following an impressive Roland Garros campaign.