After a close call against powerhouse Russia, San Antonio Spurs affiliate Erazem Lorbek needed a bounce back game against Greece.
However, the Slovenians had a big third quarter push, outscoring the Greeks 21-7 in the period to take a two-point lead, 46-44 entering the fourth quarter.
But Slovenia could not hold on to their momentum, as the Greeks turned on the pressure in the final period, scoring 25 points while holding Slovenia to just 14.
Greece handed Slovenia their second straight loss at the 2011 EuroBasket with a 69-60 decision.
Jaka Lakovic led Slovenia with 14 points, while Lorbek had 10 points, five rebounds, two assists and two steals in 35 minutes of action.
Nikos Zisis had a game-high 19 points for Greece.
Lorbek and Slovenia will play against Macedonia on Saturday.