Goals from Siyabulela Shai and Kurt Lentjies were enough to hand the Team of Choice their first win of the 2015/16 season under new coach Clive Barker.
It was the visitors who got off to the desired start as they managed the first effort on goal in the 3rd minute, but Sithole's effort from range did little to trouble Salie's goal.
It took Maritzburg a little over 15 minutes to break through the Cosmos defence as Ryan De Jongh did well down the right flank but his cross was well read by Naicker, who palmed the ball to safety ahead of Anas.
Once the home side got into their rhythm, Naicker was called into action a couple of times to deny Maritzburg the opener.
In the 34th minute, Anas had a great opportunity to open the scoring but Cosmos' captain Nsabiyumva did excellently to block the striker's effort from six yards out.
10 minutes later, it was Shai who found some space between the Ezenkosi midfield and defence, and unleashed an instictive longe-range effort which caught Naicker off-guard to hand Barker's side the lead.
Things went from bad to worse for the away side when Thato Sithole was sent for an early shower for a reckless studs-up challenge on Shai, and Comsos was reduced to 10 men on the stroke of half-time.
Marutzburg then continued where they left off in the first-half as they were awarded a penalty in the 56th minute, after Paintsil's free-kick was adjudged to have struck a hand in the Cosmos wall.
Lentijies cooly slotted home from the spot to double his team's lead, and cap off a fine showing in midfield.
The Team of Choice then became too comfortable with their two-goal advantage and allowed Jampies' 76th minute free-kick to float beyond the defence and into goal to give the Rosettenville-based side a glimmer of hope.
However, it was too little too late from Cosmos as Maritzburg picked up their first win of the season and joined SuperSport United in the TKO quarter-final draw on Monday.