Second-half goals by Knox Mutizwa and Lerato Lamola handed Arrows a valuable away win.
After a cagey first-half, Mutizwa scored an excellent volley to put the visitors in front. With United pushing numbers forward, Lamola punished them on the counter attack in the final moments of the game.
In true local derby fashion, the game got off to a flyer with both sides not holding back with their tackles.
Right-back Siyanda Zwane had the first chance to manufacture a goal scoring opportunity for the visitors in the 16th minute. He burst down the right-flank and delivered a dangerous cross into the box but Richard Ofori came out and caught the ball well.
The Team of Choice looked to make some headway down the left where Siphesihle Ndlovu and Mxolisi Kunene were operating but every time they combined, Arrows found a way to stop their threat.
In the 26th minute, Zwane picked out an unmarked Danny Phiri with another of his trademark crosses however the midfielder flashed his header over the bar.
Maritzburg almost got off to a perfect start in the second-half. Xulu picked out Mokate who ran at the Arrows defence and fired a stinging shot but Gumede made a fine save to deny him.
With a minute to go before the hour mark, Fadlu Davids side should have taken the lead.
Ndlovu showed great skill to get into the box and lay the ball on a plate for Fortune Makaringe who had time and space but shot straight at an outstretched Gumede.
It was a wasted chance and Arrows made Maritzburg pay for it in the 75th minute. Phiri's shot was blocked by Siyanda Xulu and the ball popped for Mutizwa inside the box who took a touch and acrobatically volleyed the ball past Ofori.
Ndlovu almost got his side level after Makaringe picked him out at the edge of the box in the 78th minute.
Maritzburg, however, were again denied by Gumede who tipped Ndlovu's shot over.
The Bafana Bafana midfielder found himself in the heart of the action with two minutes to go.
Substitute Deolin Mekoa headed the ball down for Ndlovu who took it in his stride and flashed a low shot but went agonisingly wide for the home side.
Arrows then delivered a decisve blow. With Maritzburg throwing numbers forward, Abafana Besthende launched a quick counter attack, which was rounded off by Lamola who ran clear and beat Ofori with a low finish.