|Lorenzo Williams was Ventspils' top scorer with 14 points|
Ventspils used a stunning second quarter to turn the tables on BC Zepter Vienna after a slow start, but were still left hanging on at the end for a 78-71 victory in Austria.
Ventspils rattled off a 31-7 run in a little over 10 minutes to turn a 25-14 deficit into a 45-32 lead before half-time.
They seemed poised to cruise home with their slow start behind them, but Vienna fought back to within three points with 19 seconds left before Ventspils salted it away from the free throw line.
Vienna dominated the early going, and led 25-14 when Nikola Pavlicevic completed a three-point play from the line with 35 seconds left in the first quarter.
But Sandis Valters responded with a three before the buzzer sounded and it was just a taste of things to come as Ventspils found their stride.
Anatoly Kashirov kept the points coming and when Valters hit another three it was 27-24 barely two minutes into the second quarter.
Artjoms Butjankovs hit the three which put them on top at the 4:30 mark and it was the 22-year-old again with the lay-up which made it 45-32 to cap the run.
Vienna tried their best to keep the gap in single figures during the third quarter but still came out of it down 60-49, and they were still down 74-66 with less than two minutes to go.
But free throws from Benedikt Danek and Nenad Sulovic closed that gap quickly to make it 74-71 with 19 ticks left.
Lorenzo Williams padded the Ventspils lead with two from the line 12 seconds from time and after Pavlicevic missed a three, Janis Timma finished the job.
Williams led Ventspils with 14 points while Valters added 11 and Timma collected 10 with 12 rebounds.
Predrag Miletic had 17 points for Vienna with Pavlicevic collecting 16.
Vienna Head Coach Darko Russo:
"We lost the game because we played a very bad second quarter. We tried to come back, but our mistakes decided the game."
Vienna Player Benedikt Danek:
"Today we played against a very strong team. In the second quarter we made too many mistakes, that is the reason why we lost the game."
Ventspils Head Coach Roberts Stelmahers:
"We knew that Vienna is a strong team. We came here to give 100 percent, we prepared very well. In the game we made some mistakes, but we are happy about this victory. Every victory in the EuroChallenge is important."
Ventspils Player Janis Timma:
"Every game on the road is tough. We started too soft on offence and defence. In the second quarter we started to play better and stronger. I am happy with how we came back."