Ukraine's women opened up a 21-point lead late in the third quarter but then had to hold on for dear life before defeating Great Britain on Saturday.
Olexandra Gorbunova had 26 points and seven rebounds for Volodymyr Bryukhovetskiy's team, which committed 23 turnovers but still won 80-73 to improve to 4-1 and remain at the top of Group A in EuroBasket Women qualifying.
Playing in Cardiff, Wales, Ukraine were in command by half-time with a 47-34 advantage and they had a 71-50 stranglehold on proceedings with 51 seconds to play in the third quarter.
Gorbunova and Co then went cold in the fourth quarter, scoring just six points and turning the ball over eight times as Britain closed the gap to 77-73.
They had a chance to draw even closer but with 18 seconds to go, Britain's Rosalee Mason missed with a jumper and Ukraine rebounded.
Inna Yegorova drilled a three right before the death for the seven-point Ukraine victory.
Kimberly Butler scored 26 points and pulled down five boards for Britain, who dropped to 1-4 in Group A.