The Rossoneri were clearly chomping at the bit to extend their lead at the top of Serie A, and the hosts found the back of the net through Rafael Leão with the very first opportunity of the game.
The Portuguese international forward collected the ball on the left flank before cutting onto his right foot, and drilling home a superb effort from just over 20 yards out in the seventh minute to give AC Milan the lead and secure his third league goal of the season.
Despite their solid work rate, the visitors failed to register a shot on target before half time. However, the dynamic of the game shifted significantly shortly before the hour mark, when a lengthy VAR check saw Pisa awarded a penalty, after Koni De Winter handballed inside his own 18-yard area.
Substitute Juan Cuadrado stepped up to take the spot-kick, and he confidently slotted the ball home to equalise and stun the home crowd into silence.
After their first home goal conceded to Pisa since May 1984, the Rossoneri were forced to move up a gear and came close to retaking the lead only four minutes after Pisa’s leveller, when Leão’s effort from inside the penalty area clipped the bar.
With 20 minutes of normal time remaining, Adrian Šemper then made a vital save to deny an incredible 35-yard effort from Belgian international Alexis Saelemaekers. That maintained Pisa’s once remote-looking hopes of a first away point against Milan since January 1989.
But with time beginning to run out, Pisa looked like they would end up getting much more than that, and remarkably took the lead for the first time in the game when M’Bala Nzola kept his composure to coolly place the ball past Mike Maignan on 86 minutes.
However, just as it looked like the visitors were on course for an astonishing away victory, the hosts equalised in the third minute of stoppage time through Zachary Athekame to break the hearts of the travelling Pisa supporters.
The hosts then came desperately close to securing a 3-2 victory with literally the last kick of the game, when a dazzling solo run from Saelemaekers almost materialised in a last-gasp winner.
Despite dropping two points in a game they were largely expected to win, AC Milan sit two points clear of arch-rivals Inter Milan at the top of Serie A, though with Inter, Napoli and Roma all capable of catching them later this weekend, there is a distinctly negative feel to this result for Milan.
Meanwhile, despite just missing out on a very famous three points, a brave and resilient Pisa have at least moved off the bottom of the table and into 18th position.
Flashscore Man of the Match: Alexis Saelemaekers (AC Milan)