The hosts had the best chance in an uneventful start to the match as Diego Novaretti planted his header over the bar, having met a free kick in the 19th minute.
Lazio had a great chance to level things up again eight minutes after the restart as Antonio Candreva unleashed a powerful effort from the edge of the box that Marco Amelia did well to keep out.
They came close again just three minutes later as Lucas Biglia fired a rebound towards goal, but a Milan defender got across to make a crucial block.
They did finally get their equaliser just after the hour mark, however, as Alvaro Gonzalez reacted quickly to flick on from a cross, diverting a header of his own past the keeper.
Milan almost regained their advantage with 10 minutes remaining in the match as Giampaolo Pazzini went for goal from inside the box, but his effort went just wide.
They were inches away from grabbing a winner in the 83rd minute as Mario Balotelli received the ball on the edge of the box before crashing an shot against the post.
Neither side could find another goal in the closing stages, however, as the spoils were shared in Rome.