In 2015-16 season Žemaitis won silver medals with club, averaging 9 points and 3,4 assists per game.

In April 2017, Vytautas Prienai–Birštonas registered him for rest of the season, because, half of the team was injured, and by the LKL rules they can't sign any player who's older than 21 years old.

On November 23, 2019, he has signed with Nevėžis Kėdainiai of the Lithuanian Basketball League.

[4] Žemaitis debuted for the Lithuania men's u-18 basketball team in the 2014 FIBA Europe Under-18 Championship in Turkey.

[5] He won silver medals with the Lithuania men's national u-20 basketball team in 2016 FIBA Europe Under-20 Championship.