Turning Point: Lithuania led 41-35 at the start of the third quarter when Portugal were hit with a bench technical and then a technical on coach Mario Palma that sparked a 10-0 run for the hosts.
Game Hero: Lithuania's Sarunas Jasikevicius had six of his 14 points in the third quarter.
Stats Don't Lie: Lithuania got 48 points from their bench compared to Portugal's 21. Lithuania out-rebounded Portugal 40-26.
Lithuania pulled away early in the third quarter to claim a 98-69 victory over Portugal on Monday night in Panevezys.
Blown out by Spain 24 hours earlier, Kestutis Kemzura's men bounced back from their first loss at the EuroBasket to secure their third win in the tournament.
"It was important for us to get a good victory after yesterday's result," said Lithuania's Simas Jasaitis, who was one of five Lithuanian players that finished in double figures.
"I think we did that and we head to Vilnius feeling good about ourselves."
The hosts, who had clinched second spot in Group A ahead of the game, will advance to Round Two in Vilnius with a 1-1 record.
Portugal, meanwhile, must go home after losing for the fifth time in the competition.
However, they pushed Lithuania early on.
Lithuania led 32-16 after 12 minutes when Portugal went on a 17-2 run to cut the gap 34-33 with 1:23 to go in the first half.
The hosts went on a 7-1 surge to go into the break with a 41-35 advantage.
Lithuania went on a 19-6 run over the next four minutes to pull away for good.
Martynas Pocius and Sarunas Jasikevicius had 14 points apiece for the Baltic side while Carlos Andrade led Portugal with 16 points.