October 17, 2020. Zlatan Ibrahimovic's double proved enough for Milan to claim a derby day victory over their great rivals, with Romelu Lukaku's goal not enough to inspire a comeback.
Much has changed in the intervening period between then and now.
Inter recovered from that defeat by going on to win the Serie A title for the first time since 2010. Yet coach Antonio Conte and talisman Lukaku have both departed for pastures new – London, to be precise, with Tottenham and Chelsea respectively.
Milan, meanwhile, finished second, 12 points behind their neighbours, but they have had a relatively settled period under Stefano Pioli. And on Saturday, the Rossoneri truly ignited the 2021-22 title race by ending Inter's domestic unbeaten streak at San Siro – a run that stretched to 28 matches in total, since that day in October 2020.
There was no Ibrahimovic for Pioli to call on this time, but another veteran forward stepped up in the form of Olivier Giroud, whose quickfire double did the damage.
Having been on the verge of going seven points clear, the incredible turnaround leaves Inter just one point above Milan, as the title battle between the two northern powerhouses looks set to go down to the wire.
Giroud brings the Z factor
Ibrahimovic is a big miss in any game, but in particular, a derby with title hopes resting on it.
The 40-year-old has scored eight Serie A goals in Milan Derbies (six for AC Milan, two for Inter) – only Giuseppe Meazza (12), Gunnar Nordahl (11) and Stefano Nyers (11) have scored more times in this fixture in the history of the competition.
For much of Saturday's clash – 75 minutes, in fact – the void in Milan's attack was evident, the Rossoneri having managed just one attempt on target, from Sandro Tonali in the first half.
But Giroud turned that on its head, first showing his poacher's instinct to prod in from Brahim Diaz's shot-cross, before holding off his marker and drilling in a low strike on the turn three minutes later.
Samir Handanovic should have done better to prevent Milan's winner, mind. Perhaps the Inter goalkeeper had been caught unawares, given his lack of action prior to the late red-and-black charge.
"Playing with him is something I see as a challenge, something that pushes me every day," Giroud said of Ibrahimovic in a recent interview.
"It's an opportunity to have him as my partner, to learn something more. He's an example for many strikers and when I was young I loved him, both on the pitch and for his strong character, and for the fact that he's demanding every day. It's a healthy competition between us."
Giroud proved an old dog can still learn new tricks (from an older dog, that is) with his match-winning turn. The former Chelsea forward converted both of his two attempts, which came from two of his four touches in the penalty area, and a combined expected goals (xG) value of 0.8, as he became the first French player to score twice against Inter in a Serie A match.
All seven of Giroud's Serie A goals this season have come at San Siro, with those strikes coming only when he has started games (eight starts in total).
Inter's charge hits its first hurdle?
There has been a pretty seamless transition for Inter since Simone Inzaghi replaced Antonio Conte.
Edin Dzeko has come in for Lukaku, and Lautaro Martinez is still brilliant. Indeed, Inter are scoring at a similar rate to last season, netting on average every 38 minutes in the league.
Yet they more than met their match in the form of Milan, who earned a thrilling 1-1 draw in the reverse fixture in November.
Inter had less possession (46 per cent) and won fewer duels (42 compared to 57), yet still created more chances (nine to seven) and had more attempts (11 to 10). They were unable to make the most of going ahead, though.
Ivan Perisic's goal – his 50th for the club – had the Nerazzurri in front by half-time but Inter have now failed to win three of their last four derby clashes, while Milan came from behind to beat them in Serie A for the first time since February 2004.
This result can hardly be considered as putting Inter into anything resembling a crisis. They have lost just two of their last 12 Serie A derbies and are still top, with a game in hand on their title rivals, though the manner of the defeat may take some coming back from.
Since the turn of the year, Inter have taken seven of the 12 points on offer and, in a title race with such fine margins (Napoli are only four points back in third), that has enabled the challengers to gain ground.
One positive for Inter, however, was a late red card for Theo Hernandez, who will face a suspension after lunging in recklessly on Denzel Dumfries.
Hernandez is one of Milan's best players, and his absence may just mean that, even though Inter lost the battle, they could go on to win the war provided they bounce back quickly.