Stefano Pioli's wait for his first win as AC Milan coach continues after Davide Calabria's error gifted Roma a 2-1 victory in Sunday's Serie A encounter. (More Football News)
Having come on shortly after half-time, right-back Calabria made an immediate impact when he teed up Theo Hernandez's equaliser in the 55th minute at Stadio Olimpico.
Hernandez's effort cancelled out Edin Dzeko's first-half opener, but Calabria ruined his good work when his loose ball enabled Nicolo Zaniolo to restore Roma's lead.
Gianluca Mancini's poor miss kept Milan's hopes alive but their new coach failed to inspire a comeback as the Rossoneri remain entrenched in the mid-table.
Milan had the better of the opening stages, Franck Kessie's slide-rule pass splitting Roma's defence in the 16th minute, but Lucas Paqueta strayed offside before drilling under Pau Lopez.
Javier Pastore failed to capitalise on a Kessie error soon after, though Dzeko made no such mistake in the 38th minute, heading home unmarked at the far post after a corner was flicked on.
Pastore would have doubled Roma's lead before the break if not for Gianluigi Donnarumma's fantastic save, and Milan's goalkeeper was left rooted to the spot when Chris Smalling sent a close-range header wide.
Smalling's frustration was compounded when he deflected Hernandez's volley beyond Lopez after Milan's left-back connected with Calabria's cross.
Parity lasted just three minutes, however - Dzeko pouncing on Calabria's slack pass to turn provider for Zaniolo, who coolly whipped a low finish into the left corner.
Mancini should have doubled Roma's advantage with a free header, but Milan could not make their hosts pay for the midfielder's profligacy, with Hakan Calhanoglu missing a pair of late attempts to draw level.
What does it mean? Pioli's tenure yet to lift off
Marco Giampaolo oversaw a 2-1 comeback victory over Genoa in his final outing as Milan coach, as it appeared the former Sampdoria boss had finally found a winning formula.
But Milan elected to cut his spell short over the international break and take a punt on Pioli. Although the Rossoneri's football has been more incisive, their soft defence has left the ex-Inter coach with just one point from his first two matches.
Clinical Dzeko shows Milan what they are missing
Roma's number nine had failed to score in his three previous outings in all competitions but was in the right place at the right time to nose Paulo Fonseca's side ahead on Sunday.
With Krzysztof Piatek failing to recapture last season's form in 2019-20 and Rafael Leao still learning his trade, what Milan would give to have a striker of Dzeko's pedigree leading their line.
Calabria suffers a swift fall from grace
Pioli's call to replace the struggling Andrea Conti quickly paid dividends when Calabria provided an exceptional cross into Hernandez. However, he went from super-sub to a dud when he tried a risky pass which was easily cut out by Dzeko ahead of Zaniolo's strike.
What's next?
Roma visit Udinese on Wednesday, while Milan are in action against struggling SPAL a day later.
