Partizan retain Serbian double
Captain Nenad Djordjevic broke the deadlock on the hour with a superb free kick from 25 metres after a dull first half.
Left back Ivan Stevanovic made it 2-0 with a scrambled effort from close range and substitute Radoslav Petrovic headed the third after a cross from the left by winger Nemanja Tomic.
It was the first time Partizan had won back-to-back domestic doubles and they now have 21 league titles and 11 national cups in their trophy cabinet.
"We're delighted to have reaffirmed our supremacy in Serbia and we're now looking forward to a bid to qualify for the Champions League next season," Partizan coach Slavisa Jokanovic told Serbian television.
The Serbian champions go into the second qualifying round of the Champions League as they bid to reach the group stage.
"We struggled for the best part of the match tonight but in the end we managed to break down Sevojno, who deserve the plaudits for reaching the final," added Jokanovic.