On the night when Belarus stunned the fancied Turkey in the same group, GB saw off the Greeks – ranked 32 places above them – in stunning fashion.
And it was record-setting Teddy Okereafor who led the way with an Ironman performance on his 50th consecutive GB appearance with 19 points off 100% three-point shooting.
Tarik Philip (16), Gabe Olaseni (13) and Luke Nelson (10) also made key contributions as a real team effort saw off 10th-ranked Greece for the first time since 1984 and only the second time ever.
Head coach Marc Steutel’s men, who head to Turkey on Sunday, had to come from behind but held their nerve to execute an impressive late-game surge to grab a famous win.
The Greeks had given early indication of their ability to move the ball slickly in the first quarter but GB showed composure and no little offensive intent of their own early on, with seven players getting on the scoresheet for the home team as the sides went into the second period level at 23 apiece.
The Brits - without key starters Myles Hesson and Ovie Soko - made a strong start to a scrappier second, easing into a five-point lead before Greece, led by the bullish Dimitrios Agravanis, turned the tables to take an advantage of five at 38-33 into the break.
They quickly stretched it to 10 within a minute of the restart then 15 at 48-33 as they teams went into a timeout at 8.15.
An Olaseni layup pulled it back to single figures as GB got going again midway through the third with an Okereafor three bringing GB back to within three points with just over two minutes in the quarter, before he repeated the trick moments later and then again, to narrow the gap to 57-56 going into the fourth.
Okereafor nailed another triple early in the fourth and Philip added a layup as the crowd reacted wildly to GB taking a 61-57 lead via an eight-point run.
Philip’s three then a two plus a three from the livewire Nelson put Steutel’s men nine up with 5.38 to play. Jordan Williams added his first points in a GB shirt to take it to 11 with a dunk and, despite a Greek scramble, GB held strong.
Ashley Hamilton hit nine as GB’s 56% three-point shooting was key.
Agravanis hit 19 and Nikolaos Gkikas 14 as GB held their own in an even battle of the boards and executed with composure to set up their trip to Turkey.
GB's clash with Turkey will be shown live by BBC Sport online, on the app and on iPlayer. See below.