Great Britain lost their opening game of the EuroBasket finals when Belgium edged a close affair 103-90.
GB led 54-53 at half-time after a strong start to the game but found scoring hard in the third quarter as Belgium's shooters took over.
Gabe Olaseni led GB's scoring with 21 points and Dan Clark added 20, with captain Kieron Achara adding 14.
GB's second game, of five opening-round encounters, comes against hosts Turkey in Istanbul on Saturday.
In a high-scoring opening half, GB looked confident, particularly close to the basket, and kept in front for the majority of a close opening 20 minutes.
After allowing Belgium nine three-pointers in the first half, they tightened up their defence in the second.
GB led 63-55 going into the last five minutes of the third quarter, but Belgium rediscovered their shooting touch to get the lead back before ending the quarter 73-67 in front.
The Belgians reached their first 10-point lead midway through the final quarter and GB's recovery was hampered by losing three of their guards - Luke Nelson, Andrew Lawrence and Teddy Okereafor - who fouled out of the game as they tried to get their team back in the game.
"We wanted to come out here and start with a win," said Olaseni. "We have to regroup - we have another tough one tomorrow so we can't just hang our heads. We have to be positive and prepare for the next game."