However, the game between the two sides will again be overshadowed by side events as a swastika pattern was clearly seen etched onto the pitch.
The November qualifier at San Siro, which also ended in a 1-1 draw was temporarily halted by crowd trouble.
It was unclear whether the symbol was mowed into the pitch or painted on the grass, but it was clearly marked in the middle of the half Italy was attacking in the first period.
He also gave away a spot kick which Antonio Candreva converted for the equalizer in the 36th. Norway remained third - two points behind Italy following a 0-0 draw at home against Azerbaijan. Bulgaria was two points further back after winning 1-0 in Malta.
More From This Section
The result in Split saw Italy stretch its unbeaten run in qualifiers for European Championships and World Cups to 46 matches. The match got off to a lively start as Croatia was awarded a sixth-minute penalty when Davide Astori clumsily tripped Darijo Srna near the byline.
Croatia did take the lead just five minutes later, shortly after Stephan El Shaarawy tapped in from eight yards but had his goal incorrectly ruled offside.
While several Italy players were protesting to the officials, Croatia resumed play and Mandzukic scored on the counter-attack.
Italy suffered a further blow in the 27th minute when Lorenzo De Silvestri had to be carried off - clearly in agony after injuring his knee as he prevented Mateo Kovacic from scoring a second goal.
Italy was already without Marco Verratti, Daniele De Rossi, Andrea Barzagli, Giorgio Chiellini and Simone Zaza.
Buffon, who had struggled with an elbow problem all week, was hobbling and the Italy captain was substituted at halftime with a large cut on his knee.
Replacement goalkeeper Salvatore Sirigu had little to do during the second half but Ivan Perisic did hit a long-range shot which flew narrowly wide. Srna was sent off in the final minute after the Croatia captain picked up a second booking. Norway missed the opportunity to make up ground on Croatia and Italy.
Azerbaijan ended a run of five consecutive away defeats but remained fifth. In Malta, Ivelin Popov scored in the 56th minute to hand Bulgaria only its second win of the qualifying campaign.
Ilian Micanski had sent a spot kick wide for Bulgaria on the stroke of halftime after Ryan Camilleri impeded Vladimir Gadzhev.