Great Britain's men were beaten 84-67 by Turkey in Istanbul, in their second World Cup qualifying game.
Dan Clark led the visitors' scoring with 17 points in his 110th game for his country, while Gabe Olaseni had 15 points and nine rebounds.
GB led 23-10 from the start but struggled to score in the second half after Turkey began with a 17-5 run.
The result leaves Group B wide open, with GB next facing Belarus home and away in a double-header in February.
Missing three regular starters – Ovie Soko, Luke Nelson and Myles Hesson – GB made a strong start through Olaseni and were level at half-time after a tight second quarter.
A pair of three-pointers from Tarik Phillip left them trailing 60-54 at the end of the third quarter.
But led by US-born point guard Shane Larkin, who hit 22 points and added eight assists, Turkey started the last quarter 16-6 to hand GB only the third defeat of their last 15 qualifying games.
"They were able to control the game in the second half with the experience they had," said Clark.
"We were chasing the game at the end and it became difficult for us. But I'm proud of the guys."
Three of the four teams in GB's group will proceed to the second round of European qualification for the World Cup, with the final tournament being held in the Philippines, Indonesia and Japan in 2023.
Group B table
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