A good start saw Jekabpils take an early 18-9 lead halfway through the opening period, but Siauliai answered with an 11-3 run to cut the gap to a single point in a matter of minutes.
The game swung in the completely opposite direction in the second period, with the visitors going up 47-36 after a basket by Domagoj Bubalo. However, a strong end to the first half, saw the double-digit gap melt to two points at the interval.
But in the third quarter, Siauliai managed to increase their advantage to 68-62 before successfully sailing the ship home, despite a late spurt by the home side that saw Jekabpils snatch a small win that wasn't enough to change the outcome of the aggregate score.
David Dudzinski had 25 points for Siauliai, Rokas Giedraitis added 16 points, six rebounds and four assists, while Gintaras Leonavicius chipped in with 14 points and four assists.
For Jekabpils, Rinalds Sirsnins collected a team-high 22 points and seven assists, Modestas Kumpys collected 17 points, while Tyler Larson had 15 points.