The 2019 champions produced a disastrous defence of their title two years, failing to win a single match as they finished bottom of their group and crashed out in dire fashion.
It was a better start here, in the Group D opener, as Baghdad Bounedjah opened the scoring, producing a brilliant first-time finish after running onto a ball over the top.
He was denied an even better second shortly after, bringing the ball down on his chest with one touch and firing a stunning overhead kick into the back of the net with a second, only for the offside flag to be belatedly raised. The decision was, cruelly, confirmed by VAR.
Algeria were less dangerous after the break, as Angola began to offer a threat on the break and they took full advantage of their chance when it came.
Mabululu, introduced in the first-half in what appeared to be a tactical change, was brought down in the box by Nabil Bentaleb and the referee swiftly pointed to the spot. Mabululu took the spot-kick himself, crashing an effort off the underside of the bar and while the ball looked to have crossed the line, he turned home the rebound to make sure.
That left Algeria with just over 20 minutes to find a winner, but they looked increasingly tired and barely threatened the Angolan defence. They will need an improve showing in their next group-stage match, against Burkina Faso, while Angola will be eyeing a positive result against Mauritania.