A single goal was enough for Tarxien to pick up three valuable points in their battle to avoid relegation.
A penalty by Raphael Kooh Sohna just before the break was enough for Tarxien to beat Balzan who are just four points above them, one place above the bottom three.
Earlier, Gzira powered past Floriana 4-1 to go third in the premiership, six points adrift of leaders Hamrun.