Lazio looked on course for a fourth consecutive Serie A victory after establishing a two-goal advantage in the first half, but Milan transformed after the interval. Moreira's introduction proved decisive as the Portuguese attacker struck twice to bring the Rossoneri level.
The result ended Lazio's perfect start to the Serie A season, while Milan extended their unbeaten run to four matches and moved to eight points from their opening four games.
Lazio dominate the first half
Lazio made the stronger start at the Olimpico and took the lead after just 10 minutes.
Matteo Cancellieri found the breakthrough for Gennaro Gattuso's side, rewarding Lazio's bright opening and putting the hosts in control.
Milan struggled to impose themselves during the opening period, with Lazio restricting the visitors' attacking threat and controlling much of the game.
The home side doubled their advantage before the break through Tijjani Noslin, leaving Milan facing a two-goal deficit at half-time.
• Lazio: Matteo Cancellieri 10', Tijjani Noslin 39'
• AC Milan: Diego Moreira 65', 67'
Amorim's substitutions change the game
Amorim responded at half-time by making significant changes to his attacking setup, with Diego Moreira and Christian Pulisic among the players introduced as Milan searched for a route back into the match.
The changes immediately gave Milan greater energy and attacking threat.
Moreira reduced the deficit in the 65th minute after combining with Pulisic before producing a composed finish to make it 2–1.
Just two minutes later, the comeback was complete.
Moreira struck again in the 67th minute, this time finishing powerfully to bring Milan level at 2–2 and complete an extraordinary individual impact from the bench.
Milan push for a winner
The momentum had completely shifted towards Milan.
The Rossoneri dominated the second half and created further opportunities as Lazio struggled to regain the control they had enjoyed before the interval.
Milan eventually finished with 66 per cent possession, 629 passes and seven shots on target, compared with Lazio's 34 per cent possession and six shots on target.
Despite Milan's late pressure, Lazio held on for a point.
Moreira becomes Milan's unlikely hero
Moreira's two-goal intervention provided one of the defining moments of the match.
The Belgian international, who joined Milan from Strasbourg, had initially been among the substitutes but changed the contest almost single-handedly after being introduced.
For Amorim, the comeback demonstrated Milan's resilience but also exposed the need for a stronger start after a first half in which the Rossoneri were largely second best.
Lazio, meanwhile, will feel disappointed after surrendering a two-goal lead at home, but Gattuso's team remain unbeaten after four league matches.
Milan maintain unbeaten start
The draw leaves Milan with eight points from four Serie A matches, following victories over Torino and Venezia and draws against Juventus and Lazio.
Lazio move to 10 points, having won their first three matches before Saturday's comeback draw.
For Milan, the immediate positive is their unbeaten record and the impact of their substitutes. However, Amorim will know that conceding two first-half goals against a side of Lazio's quality nearly cost his team their unbeaten start.
Final result:
• Lazio: Matteo Cancellieri 10', Tijjani Noslin 39'
• AC Milan: Diego Moreira 65', 67'
Venue: Stadio Olimpico, Rome
Competition: Serie A, Matchday 4
Date: 12 September 2026