Hopkins, a 26-year-old shooting guard, erupted for a season-high 28 points as Antwerp rolled to an 88-80 victory in Group L.
Antwerp won just three of their six games in the Regular Season and travelled to Istanbul to face a Banvit side that had claimed five wins in its six games.
The Belgians tore up the form book with a dominating first half when they led by as many as 20 points.
Hopkins had 18 of his points before the break.
Banvit managed to reduce the deficit to 44-30 only for a Thomas Gardner lay-up at the end of the second quarter to give the Giants a 46-30 lead.
The home side gave the local fans cause for hope in the third-quarter when they reeled off seven unanswered points to trim a 15-point deficit to just 60-52.
Antwerp responded with a 10-1 run with Timothy Black scoring six of those points.
Banvit did go on a scoring spree in the last 2:37 that made an interesting finish.
Trailing 86-71 after Hopkins' fifth three-pointer, Keith Simmons sparked a 9-0 Banvit run by hitting a shot from the arc and then a pair of free-throws.
When Lance Williams capped the spurt with a tip-in, Banvit were behind 86-80 with just 26 seconds to play.
That was as close as they would get, with Hopkins adding a pair of free-throws for Antwerp to finish the scoring.
Simmons led Banvit with 20 points.
The Turkish team hurt its own cause by making just 24 of 35 free-throws.
Antwerp shot the ball well at the charity stripe, making 16 of 19.
Orhun Ene, Banvit Head Coach:
"We wanted to have a good start in our first game within the Top 16 teams. However, we could not play well like the way we wanted. Our rival scored a lot, while we were missing our shots. We lost the game that we did want to win. Congratulation to our rival."
Charles Davis, Banvit Forward:
"İt was necessary to win this game. We could not play well as a team. Our competitor was more willing than we were to win the game; therefore, they played very well. We congratulate the other team."