The Dutch side is now 2-1 while Dexia, who endured a late collapse last week at BC Triumph, are 1-2.
The Amsterdammers took the lead for good late in the third quarter when Clint Harrison and Tamien Trent hit back-to-back three-pointers for a 56-50 advantage.
After Dexia trimmed the deficit to 58-54 by the end of the frame, Harrison began the final quarter with another three as the Dutch team went in front by seven.
Dexia have provided European basketball with plenty of thrills the last couple of seasons but they didn't mount a successful comeback on this occasion.
Harrison ended up making four of six shots from behind the arc and led the winners with 22 points.
Teddy Gipson contributed 20, Orien Greene 16 and Peter van Paassen 12 with eight rebounds.
Caleb Green finished with 19 points for Dexia.
Teddy Gipson, EclipseJet Amsterdam:
"I thought we started well, but in the second quarter our concentration was not that good. I think we started better in the second half and then pushed through."
Chris Finch, coach Dexia Mons-Hainaut:
"We have a problem adapting to our opponents. We just play the same game over and over again. At the end I thought we didn't even deserve to win."
Nate Reinking, Dexia Mons-Hainaut:
"EclipseJet was the smarter team. They punished us for the mistakes we made."