Milan roared back from 2-0 down to beat Hellas Verona 3-2 on Saturday and claim top spot in the Serie A table.
Unbeaten in their opening seven league games of the season, the Rossoneri were 2-0 down at the break against a side previously without an away win against them in 29 attempts.
Gianluca Caprari and a penalty from Antonin Barak had Verona heading for an unlikely three points before the home side produced a second-half turnaround.
After Olivier Giroud had headed home a third goal in three league games, Franck Kessie equalised from the penalty spot before Koray Gunter's own goal settled a gripping contest.
Milan had not conceded two first-half goals in Serie A since last November – against these opponents – but they paid the price for a lifeless start to the contest.
Ciprian Tatarusanu, in for the injured Mike Maignan, was powerless to keep out Caprari's precise finish seven minutes in after Miguel Veloso had kept Verona's attack alive.
The lead was doubled 17 minutes later, Barak putting his penalty just out of Tatarusanu's reach after Alessio Romagnoli was judged to have fouled Nikola Kalinic as the former Milan forward darted in front of him to meet a cross.
This Milan is a resilient side, though – they have only twice taken more points after the first eight matches of the season in the three-point era than they had before this game – and they got a lifeline just before the hour when Giroud nodded in Rafael Leao's expert cross from the left.
A swift passing move saw Leao backheel the ball to Samu Castillejo, who was caught from behind by Marco Faraoni, allowing Kessie to dispatch a confident penalty and level the scores with 15 minutes left.
Stefano Pioli introduced Zlatan Ibrahimovic off the bench, and the veteran striker may well have had a tap-in had Gunter not scuffed an attempted clearance beneath the legs of goalkeeper Lorenzo Montipo to give Milan the lead.
What does it mean? Milan go top – and stay unbeaten
Milan's comeback saw them leapfrog Napoli, who play Torino on Sunday, and go top of the table by a single point.
With Inter having lost 3-1 at Lazio earlier, Pioli will be doubly pleased with the manner of their second-half performance as they capitalised on their rivals' first loss of the season.
Verona are 13th, with eight points from eight games.
Olivier takes centre stage
Giroud has made a career out of being a penalty-box menace and it was no surprise to see him drag Milan back into the contest.
He is the fifth Rossonero since 1994-95 to score three goals in his first two Serie A home games, after Oliver Bierhoff, Alexandre Pato, Mario Balotelli and Carlos Bacca.
Maldini goes missing
Daniel Maldini completed just seven passes before being hooked at half-time as Pioli rang the changes to good effect.
By contrast, replacement Rade Krunic completed twice as many in the opposition half alone while creating four goalscoring chances.
What's next?
Milan head to Porto in the Champions League on Tuesday before facing Bologna away on October 23.