Usuthu ended the match with 10 men after Morton was dismissed late on after an off-the-ball incident involving Gabadinho Mhango threatened to bring the game to a bitter end.
AmaZulu took a half-time lead in to the break against struggling Wits on Wednesday night at Kings Zwelithini stadium after Morton latched onto a loose ball outside the Wits penalty area, and unleashed a venomous strike in the 11th minute which gave goalkeeper Moeneeb Josephs absolutely no chance.
The goal came against the run of play, after the Clever Boys started the game very positively.
Manzini scored a penalty midway through the second half to all but seal the fate of the struggling champions as Usuthu doubled their lead. Wits midfielder Vincent Pule was adjudged to have handled the ball in the penalty area, with the referee on the spot to award the penalty. Manzini stepped up, and blasted is effort straight down the middle beating Josephs with a thumping strike.
Two minutes later, the AmaZulu striker was at it again, after he scored his second goal and his team’s third of the evening with an emphatic right-footed effort which curled beyond the beleaguered Josephs.
With 15 minutes to play, Morton was shown a straight red card for shoving Mhango to the ground after being spat at.
Cavin Johnson's charges managed to see out the closing stages of the second half with relative ease as they ran out 3-0 winners on the night.