Milan picked up three crucial points in their bid to turn their season around and secure a Champions League place.
Two goals from Giampaolo Pazzini were enough to hold off a spirited Bologna side that was organised magnificently by Stefano Pioli.
Talk is rife of new players arriving this month, but Allegri is laying a superb foundation for those reinforcements to come in and boost the bid to rise up to third in the table.
Six wins in the last eight league matches have transformed the Rossoneri's outlook on their aspirations for the rest of the season, closing the gap on third to nine points at the time of writing.
Here are six things that we learned from the game that will prove to key factors for Milan moving forward.
Giampaolo Pazzini bagged a brace in a vital win for Milan and took his tally for the season in the league to 10 goals.
While the former Inter striker padded that statistic with a hat-trick on his full debut and three penalties, they all count.
With 10 goals in 19 league appearances, Pazzini is suggesting that Milan do not need to go and buy another striker this window.
Mario Balotelli could join the Rossoneri, according to The Guardian, which would probably push the 28-year-old out of the starting lineup.
Adriano Galliani will have to think long and hard about this one, as a new signing potentially stunts Pazzini's new found form. Failing to sign a striker would be a risk, as it is unclear whether Pazzini can continue this form for the rest of the season.
Ultimately, Milan need to decide whether a quick fix in the market in order to secure Champions League football is worthwhile, or whether their hopes are too unlikely and that further signings could damage the club's finances moving forward.
Kevin Constant arrived at Milan this summer to little fanfare, but the majority of Rossoneri fans would agree that he is deserving of a start in Massimiliano Allegri's side these days.
With Luca Antonini an afterthought now, Constant is competing with Ignazio Abate and Mattia De Sciglio to start for the Rossoneri.
Constant is the only naturally left-footed full back amongst that trio, although De Sciglio is quite adept at filling in at left-back if Allegri wishes to field the dynamic Abate at right-back.
It is becoming more apparent though that De Sciglio looks a little uncomfortable at left-back and that with Constant there, De Sciglio can provide a more rounded game at right-back than Abate, who is often exposed defensively.
Constant has played the majority of his career in Italy at midfield. Chievo and Genoa mostly selected the Guinean international at left midfield or centre midfield.
It is therefore to be expected that Constant can often struggle in one-on-one situations defensively, but his outstanding combination of pace and strength mean that he can cope adequately against the majority of wide players in Serie A.
To have a left-footed left-back also gives Milan more balance when building their attacks from the back, it sharpens up the moves and means that the Rossoneri can stretch the opposition by using the entirety of the pitch.
Constant, for now, is one of the first names on Allegri's team sheet.
Much talk has centred on a bizarre suggestion from some that the Brazilian could be deployed as a regista, or in other words, Milan's deepest centre midfielder.
This seems to be wide of the mark, as Kaka has a lot more in his locker that Milan could use in the more advanced areas.
With the Real Madrid star assisting more than he ever has, totalling a career-high 14 last season, Kaka would be the most logical move to enhance Milan's chances of Champions League football for next season.
Talk of Mario Balotelli joining Milan this month, according to The Telegraph, is all well and good, but Adriano Galliani should make Kaka the priority.
As documented in the first slide, Giampaolo Pazzini is flourishing right now and Stephan El Shaarawy once led the Capocannoniere charts this season, so goals are not the main problem for Milan in an attacking sense.
The fluidity in the development of the attacks and the vision and creativity are lacking, which leads me to believe that Kaka would instantly enhance the performances of everybody around him.
Whether that would be with Robinho, Kevin-Prince Boateng, Bojan Krkic or the emerging M'Baye Niang as a right winger and Kaka tucked in behind the front three—a logical move against the weaker opposition in the league—or initially as that right winger, moving into the middle and allowing Pazzini and El Shaarawy to shuffle across to form a diamond formation, Kaka would immediately enhance this side.
Mathieu Flamini has suffered from a horrendous amount of injuries in his time with Milan and the reward of an extra year on his contract last summer was probably a goodwill gesture by the Rossoneri, rather than any faith that he could contribute to the cause.
A shadow of the player that once dominated Premier League midfield battles for Arsenal, Flamini has fell down the pecking order, starting just three Serie A games this season.
With Massimiliano Allegri putting a greater emphasis on an attack-minded quartet, including a midfielder, such as Kevin-Prince Boateng, given the license to join the front three, Milan are in need of a destroyer to accompany Riccardo Montolivo in the middle of the pitch.
Massimo Ambrosini would tend to be the first choice, especially now that Nigel De Jong has been ruled out for the remainder of the season. But the Milan veteran is reaching the end of a glittering career and becoming increasingly prone to injuries.
Sulley Muntari has struggled with injuries too and Antonio Nocerino is not quite disciplined enough to fulfil this new, integral role, so Flamini has stumbled across a vacancy that he can potentially fill.
Lacking the pace and energy he once had, Flamini needs to reinvent his game for the Rossoneri and perhaps be prepared to sacrifice his own glory by becoming a disruptive influence on the opposition, which will undoubtedly lead to numerous yellow cards.
In a game that Milan largely dominated, Bologna still found hope of escaping with a point thanks to some comical defending from Milan's centre-backs.
It is tough to criticise Massimiliano Allegri for the ineptitude of the defence, since Philippe Mexes and Cristian Zapata are probably the best combination at his disposal, but it doesn't change the fact that if Milan miss the Champions League next season, they will ultimately prove to be most culpable.
Adriano Galliani seems to have ruled out the possibility of more defensive enforcements though, insisting, "we already have five centre-backs."
That Milan have strength in depth in this department is true, but along with the two aforementioned centre-backs, the other options are Daniele Bonera, Mario Yepes and Francesco Acerbi. None of these are frankly up to the standards that Milan aspire to reach.
Christian Abbiati briefly lost his place to Marco Amelia over the last couple of months after some less than assuring form between the sticks.
While Amelia is not a liability and perhaps better than a backup goalkeeper ought to be, he does not provide a upgrade to Abbiati now, or for the foreseeable future.
Abbiati is not a long term solution to the Rossoneri in goal either, but for the moment Allegri's perseverance in him is going impede Milan's defence least.
With a shaky centre-back partnership in front of the goalkeeper, no matter who Allegri chooses, more uncertainty as to who is commanding the defence from the goal can only hurt the Rossoneri's chances building a solid defensive base moving forward.