AC Milan were held to a 0-0 draw by Bologna at the San Siro leaving them just one point in front at the top of the Serie A table.
With defending champions Inter Milan and second-placed Napoli breathing down their necks, AC Milan had to respond against a mid-table Bologna, who were without coach Sinisa Mihajlovic on the touchline as he undergoes hospital treatment for leukemia.
Milan, who had won each of their last three games 1-0, could not repeat the feat despite launching a late flurry as the visitors held firm at the San Siro.
After a decent start by Bologna, AC Milan flexed their top-of-the-table muscles with Rafael Leao, Olivier Giroud, and Brahim Diaz all going close to putting the hosts in the driving seat.
Their wastefulness was rescued by keeper Mike Maignan who flew through the air to stop Musa Barrow’s thundering shot in the 26th minute to prevent Mihajlovic’s men from taking the lead.
Davide Calabria and Theo Hernandez fired their efforts just wide as the home side responded aptly.
Lukasz Skorupski produced a fine save in first-half stoppage time to keep Giroud’s powerful header out and keep the score at 0-0.
Davide Calabria and substitute Ante Rebic were the next pair to waste chances as the home side became increasingly desperate prompting the introduction of 40-year-old maverick Ibrahimovic with 20 minutes to go.
The Sweden international and Bologna skipper Gary Medel clashed heads literally before Ibrahimovic headed just over the bar.
Skorupski made another save from Rebic in stoppage time as the visitors scrapped their way to a draw which left Milan just a point clear of second-placed Napoli.
Milan moved to 67 points ahead of Napoli on 66 with seven games to play in pursuit of their first Scudetto since 2011.
Third-placed Inter are three points further back having played a game less than their title rivals.