Musa Nyatama scored a winner right at the death after Lennox Bacela had cancelled out Diyo Sibisi’s opening goal.
Phunya Sele Sele made a bright start and could well have been up in side the first 10 minutes, but Erick Mathoho powered a header into the bar in the fourth minute and then Lennox Bacela just failed to get on the end of Moses Spandeel’s ball across the goal-line.
The Team of Choice then settled and in the 19th minute Patrick Tinyemb was forced into making a diving save to keep out John Arwuah’s 25-yard pile-driver.
The effort paid off for the KZN side as they went ahead in the 24th minute, thanks to Sibisi’s second goal in two games.
The goal was simplicity at its best, the former Free State Stars striker emphatically burying a header from eight yards out after an inch-perfect cross from Felix Obada.
Following the goal, Maritzburg remained in charge, the extra man in midfield in Bevan Fransch meaning they dominated this area of the pitch.
But despite showing promise Maritzburg coach Ernst Middendorop had to watch as several moves broke down near the edge of the area.
Just after the half hour mark Celtic had two chances in quick succession as first Mathoho directed a header from a free kick straight at Shu-aib Walters and then Bacela failed to squeeze his shot in at the near post after a route-one ball had taken him clear of the United defence.
But with four minutes to go before the break there was no denying Bacela as he levelled scores, the Knysna-born marksman taking the ball off Fabian McCarthy before finishing with an outstanding effort from a very tight angle.
Open stages of the second half were tight, with the first opening appearing to fall to Sibisi, but Mathoho moved sharply to snuff out the danger.
Celtic did appear to be buoyed by the goal before half time and after the break it was them who made most of the running – with no end product however as too much hesitancy was shown in front of goal.
The visitors showed themselves to be a threat on the break and should have scored on one such occasion, but Obada skewed his 66th minute shot all wide after a neat one-two with Sibisi.
With 15 minutes of regulation time Celtic keeper Tinyemb did superbly to keep the hosts in the game when he made a brilliant reflex save to deny Mor Diouf’s thunderous free-kick.
By this stage the game was wide open and when Celtic broke swiftly, Bacela should have done better when he found himself open from a cross, but he sent a volley well wide.
Both teams had put in major effort and as the game approached 90 minutes, it appeared as if things were easing off with extra time on the horizon.
But Maritzburg launched an 89th minute attack with Rudolf Bester prominent.
The Namibian slipped the ball in for Nyatama, who cut back inside before firing goal-wards and seeing his shot take a kind deflection off a defender and into the back of the net for a dramatic late win to break the hearts of Clinton Larsen’s team.