Ndulula scored against his own team in the first half, after a great solo run, to give Usuthu the three points, while visiting goalkeeper Aubrey Mathibe put in a Man of the Match performance.
The first chance of the match fell to new Bucs signing Kermit Erasmus, who forced Mathibe into a save in only the third minute.
With the home team pressing tirelessly, an unmarked Happy Jele should have headed home in the 13th minute after a teasing cross from William Twala from the right flank, but he failed to convert.
Another disappointing finish followed for Hele around the half hour mark as he watch a shot go over the bar.
With Bucs going forward in numbers, Usuthu got a chance to break and Ndulula danced past two Pirates defenders with ease before a stunning finish.
Bucs could have levelled two minutes before half-time when Erasmus hit a shot slightly off target after a Sifiso Myeni free-kick.
After Pirates’ early dominance, AmaZulu slowly settled into the game but their neat passing was fruitless as they struggled to break down the Pirates defence.
Erasmus tried a number of close-range efforts in the second half, but none could beat Mathibe.
With 25 minutes to play another chance went begging for Pirates when the ball fell kindly for Matlaba at the edge of the box, but he pulled his shot across the face of the goal.
Towards the end of the match Andile Jali had a chance skewed the ball over the bar.
The last chance fell to Matlaba, but it was not to be as he was denied again by Mathibe.