ASK Riga won 83-69 in Latvia over Cajasol on Wednesday to take the upper hand in their EuroCup Qualifying Round 2 showdown.
The two sides will meet again next week with the aggregate score of the two games deciding which team will advance to the EuroCup Regular Season.
Bruno Sundov paced the Latvia giants with 21 points and eight rebounds while Ricardo Marsh poured in 19 and pulled down seven rebounds.
Corey Brewer also had nine points, seven rebounds and five assists for ASK Riga but the American was just three of 14 from the floor, including two of seven from long range.
The home side was on top at 70-65 when it broke away for a convincing triumph.
Sundov drilled a three-pointer and Uvis Helmanis caught a pass by Brewer and buried a jump shot for a 76-65 advantage.
Marsh and Sundov followed with baskets to open up a 14-point lead.
Sandis Valters extended the advantage to 16 with a pair of free throws before Andrea Pecile finished off the scoring with two from the stripe for Cajasol.
The Spanish outfit turned the ball over 22 times. They were led by Warren Carter's 15 points.