Super-sub Joaquin had a hand in both of his side's goals as Fiorentina came from behind to beat Milan 2-1 on Monday.
Joaquin made his case for a starting place, scoring the first and assisting the second as Fiorentina struck late to beat Milan 2-1 on Monday.
The hosts had fallen behind at a sodden Stade Artemi Franchi when Mattia Destro rewarded under-pressure Filippo Inzaghi's decision to reinstate him to Milan's starting lineup.
However, winger Joaquin, introduced at halftime, helped to turn the tide for Vincenzo Montella's men as he produced a delightful cross for Gonzalo Rodriguez to head home seven minutes from time.
Fiorentina - missing the likes of David Pizarro, Mario Gomez, Stefan Savic and Giuseppe Rossi due to injury - looked to be tiring prior to the equalizer after a hectic run of fixtures including UEFA Europa League and Coppa Italia commitments.
However, the home side continued to press and was rewarded when Joaquin headed home Manuel Pasqual's delivery late on to bolster the team's hopes of European qualification.
Inzaghi's men were left to lament their inability to see the game out as they succumbed to late goals in back-to-back Serie A outings, with questions about the former striker's future in the Milan hot seat bound to follow.
A Milan win would have truly been a smash-and-grab effort with Fiorentina controlling much of the contest and going close early with a fierce Josip Ilicic effort six minutes in, before Keisuke Honda blasted Milan's first opening at Neto.
Honda was played through on goal after some slick build-up with Jeremy Menez, only to see his shot deflected behind by Aleandro Rosi.
Jose Basanta had the best chance of the opening half hour, crashing Ilicic's free kick against Diego Lopez's crossbar from close range. Fiorentina continued to knock on the door when the second half eventually resumed amid torrential rain.
Greatly against the run of play, Milan went in front when Destro diverted Giacomo Bonaventura's wayward effort past a helpless Neto following a quick break.
Destro's second goal for the San Siro club failed to halt the home team's advances. And incessant Fiorentina pressure finally paid off in the 83rd minute as Rodriguez rose to nod Joaquin's cross home.
Milan's misery was compounded a minute from the end of normal time as Joaquin was left free to head beyond a helpless Lopez, leaving Inzaghi clinging to his job as his side sits well adrift of the race for Europe.