Djalma cancelled out Youssef Msakni’s first-half penalty to earn Angola a point against Tunisia in the Africa Cup of Nations.
The 32-year-old fired home on the rebound after goalkeeper Farouk Ben Mustapha failed to hold on to Mateus’ goal-bound effort.
Msakni had given Tunisia the lead from the spot 11 minutes before half-time.
Mali face Mauritania in Group E’s other game later on Monday (21:00 BST kick-off).
Tunisia came into the tournament as the second-highest-placed African nation in Fifa’s world rankings but struggled for long periods against Angola, who deserved their point after dominating possession in the second half.
The Palancas Negras went closest to taking the lead prior to Msakni’s opener, Wilson Eduardo running on to Stelvio’s pass before drilling just wide of the far post.
Alain Giresse’s side took the lead when Msakni stroked home from the spot after Naim Sliti had been tripped by Paizo inside the area.
Angola dominated the second half without creating many clear-cut opportunities, but earned a point through Djalma’s strike.
Former Sunderland player Wabhi Kazhri curled a low shot off target late on as Tunisia pushed for a winner, while Angola goalkeeper Tony Cabaca saved another Msaki effort in second-half stoppage time.
Tunisia face Mali in their next group match on Friday (15:30 kick-off), while Angola take on Mauritania on Saturday (15:30).