Great Britain suffered an 82-60 defeat by France in their opening game of the 2012 Olympic test event tournament.
The home side led for much of the opening quarter but France soon settled into their game and enjoyed a superior conversion rate to secure victory.
"At moments we played well but at other moments we played like a young team, which of course we are," said Great Britain coach Chris Finch.
"I told our guys to learn quickly and get ready for tomorrow."
Joel Freeland led the scoring for Britain with 16, while Tony Parker was top scorer for France with 23.
The event was the first to take place on the Olympic Park as Games organisers test the venue ahead of next summer.
All of the 3,000 tickets on offer sold out as fans got their first taste of the teams who could line up at next summer's Games - and they were treated to some lively play from a France team with six current NBA players in their squad.
Both teams lacked fluidity as they fought to take control of what was a scrappy opening half. The teams had difficulty keeping possession with GB racking up seven turnovers and France 10 by half-time.
However, there were flashes of excellence by GB through 18-year-old Devon van Oostrum, who netted a three-pointer, followed closely by Mike Lenzly, extending GB's lead to 13-7 with four minutes 12 seconds left to play in the opening quarter.
France's offence was led by the experienced Parker from tip-off and caused the GB defence real problems.
The San Antonio Spurs player amassed 10 points in the opening quarter on his way to 25 on the night.
In the second quarter, France felt the absence of Parker, who had been rested, as they went more than five minutes without a basket.
But the French soon began to exert their authority and Nicolas Batum excited the crowd with an acrobatic move to help his team to a six-point run that lifted them into a 26-24 lead.
With Parker reinstated for the third, France continued to outplay their opponents to go in 60-48 ahead at the end of the quarter.
GB threatened to retake the lead in the final period, going on a six-point run to reduce France's lead to eight points with six minutes on the clock.
But a series of errors and turnovers, most notably by Ogo Adegboye who had the ball stolen and converted from under his own net, allowed France to stretch their lead further.
Fresh legs were introduced late on for GB in Ryan Richards but to no avail as France maintained their superiority, netting 52% of their field goals compared to GB's 33%, to complete the win.
France's Boris Diaw said: "I think it was the pressure we put on them the whole game and the energy we had - we never stopped. I think that got them tired.
"GB player Joel Freeland played a great game, had a lot of rebounds and was a big presence defensively in the paint.
"We've been seeing for the past few years GB have got better and better and now we're looking at that improvement as they're preparing for 2012."
GB captain Drew Sullivan said: "I had chances to make plays. I've got to try and do that more often but those points make no difference when the team loses."
Earlier in the day, China lost 71-43 to Australia with Peter Crawford leading the scoring for the Australians with 15, while Serbia, ranked eighth in the world, lost 83-71 to Croatia.
In Wednesday's games, China take on Serbia (1500 BST), France play Australia (1800 BST) and GB clash with Croatia (2030 BST).
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