Great Britain lost 81-61 away to Lithuania in their first defeat of the qualifiers for next year's EuroBasket.
Forward Temi Fagbenle scored 16 points but couldn't stop GB slipping to defeat against the unbeaten group leaders.
The visitors led 20-11 early in the second quarter in Kedainiai but trailed by five points at half-time.
Lithuania extended their lead to 14 points in a one-sided third quarter and added 23 more points in the fourth quarter to seal an emphatic victory.
Stef Collins, one of the smallest players on the court, completed a fine double-double of 14 points and 10 rebounds.
Head Coach Peter Buckle said: "I think that, while the score suggested a blowout, it was a really hard-fought game at times - especially in the first-half which was a battle."
GB play Belgium, who beat Macedonia 94-66 in the other group game, in Antwerp on Wednesday in a game that will be vital to both sides' chances of qualifying.
After GB took the initiative in the second quarter, Lithuania responded with a 21-3 run that gave them an edge they never seemed likely to lose.
The hosts hit 22 of the first 32 points of the second half to lead 57-40 and cruised to their third successive group win.