Eight minutes into the first quarter, the visitors from Lithuania had a 14-10 lead, but Augustas Peciukevicius finished the period with a personal show, as the Tartu club shot ahead with a 7-0 run.
Rock’s point guard from Lithuania drained a three-pointer, assisted Vincent Simpson on the break after a steal and then scored a last-second lay-up to finish the quarter to give the hosts a 17-14 edge.
However, Prienai regained the lead with a strong start of the second quarter, winning the six-minute stretch 18-2 to gain a 32-19 advantage, with Gert Dorbek ending the run with a three-pointer.
Having cut the gap 31-38 with a quick 5-0 to end the half, Rock fell back by double digits again in the third quarter, trailing Prienai 45-58 before the final period.
The Lithuanian team led by as many as 18 points in the fourth quarter, but the Tartu club went on a huge 23-3 run to jump ahead 71-69 with under a minute remaining.
However, Gintaras Kadziulis drove to the basket and scored a lay-up with three seconds left to send the game into overtime.
Rock gained an early four-point advantage in the extra period, but a couple of big three-pointers by Mindaugas Lukauskis kept Prienai in the game, tying the game at 79-79 with 23 seconds remaining.
However, Janar Talts had the last say in the game, slamming down a powerful dunk after a perfectly executed pick-and-roll with Augustas Peciukevicius to score the game-winning basket with four seconds on the clock.
Talts finished the game with 16 points, six rebounds and five assists, while Peciukevicius had 15 points, seven rebounds and six assists. Tanel Kurbas finished the game with 16 points and eight boards.
For Prienai, the team’s newcomer Mindaugas Lukauskis had 22 points, Gintaras Kadziulis scored 16, with Arturas Valeika chipping in with 12 points and nine rebounds.