Sinisa Mihajlovic's maiden Serie A game in charge of Milan ended in a 2-0 loss at Paulo Sousa's Fiorentina on Sunday.
Josip Ilicic was in spectacular form as Paulo Sousa's Fiorentina saw off 10-man Milan 2-0 at the Stadio Artemio Franchi to get off to a winning start in Serie A.
The Slovenia midfielder was the heart of some fantastic free-flowing moves and was rewarded for his efforts when he put the hosts further ahead from the penalty spot following Marcos Alonso's superb opener before half-time.
Fiorentina were terrific in the first half, and, after Ilicic went close and new signing Nikola Kalinic squandered a gilt-edged chance, Sousa's men were boosted by the sending off of Milan defender Rodrigo Ely on his Serie A debut.
And Fiorentina wasted no time in making the most of their numerical advantage, Alonso converting with a curling strike from the resulting free-kick.
Defeat highlights the size of the job ahead at Milan facing new coach Sinisa Mihajlovic, who succeeded Filippo Inzaghi at San Siro, while Sousa replaced Vincenzo Montella in a close-season of managerial change for both clubs.
The hosts started brightly, Ilicic almost catching Diego Lopez off guard with a long-range effort that forced the Milan goalkeeper into an instinctive stop.
Mihajlovic has spent big money to add 20-year-old Alessio Romagnoli to his defence, choosing to pair him with Ely, who has spent the last three seasons out on loan, in a youthful partnership.
But the duo were hapless as the increasingly influential Ilicic played through debutant Kalinic, only for the former Blackburn striker to fire a tame shot straight at Lopez.
Milan should have taken the lead against the run of play when Giacomo Bonaventura latched onto a cross at the back post, only to skew his header wide.
Fiorentina continued to flood forward, though, and Ely's milestone appearance came to a nightmare end after 36 minutes when he received his second yellow after bringing down Kalinic.
Milan's misery was compounded moments later, Real Madrid academy graduate Alonso stepping up to dispatch the free-kick into the top-left corner.
After a promising start to the second half for the visitors, Milan's defence was penetrated again as Federico Bernardeschi found Ilicic, who forced Lopez into another fantastic stop.
Ilicic was not to be denied a goal, however, and, after being taken down by Romagnoli following a surge into the Milan area, he calmly drilled the penalty low into the right corner.
Carlos Bacca, starved of service throughout his Serie A bow, should have directed a free header on target with 15 minutes remaining, but that was all that Milan could muster as Fiorentina eased to a comfortable victory.