Maroussi edged ASK Riga to record their third consecutive win in the EuroCup.
The Athens club, struggling in the Greek domestic league, have found Europe to be an oasis and now look good bets to progress to the next round from Group F after a 62-60 success in Latvia.
In a battle off unbeatens, Maroussi led 61-59 with 28 seconds to go when they fouled Curtis Millage and put him on the line.
Millage made the first but missed the second attempt, however, he grabbed the offensive rebound and Riga maintained possession until Millage again had a chance to be the hero, only to miss a lay-up with seven seconds to play.
Maroussi rebounded, and Riga fouled to stop the clock with three seconds left.
Christoforos Stefanidis could have given Maroussi a three-point lead but missed the first attempt while sinking the second.
Riga called timeout, and when play resumed, the hosts got the ball into the hands of Steponas Babrauskas but his attempted three-pointer was off the mark and Maroussi escaped with a two-point victory.
The defeat will be a difficult pill to swallow for Riga, who enjoyed a 40-30 lead at half-time.
Maroussi limited their hosts to just eight third-quarter points, however, and took a 49-48 advantage into the final period before scraping out a victory.
Ermin Jazvin had 15 points, five rebounds and blocked two shots for Maroussi, who also got 14 points from Christopher Thomas and 12 from Renaldas Seibutis.
Riga were paced by Millage's 15 points.