Allegri's side pushed four points clear at the top with a thrilling 3-2 win over a 10-man Inter at San Siro on Saturday.
Napoli can move that buffer back to one with three games left with a win at Fiorentina on Sunday.
Allegri feels Maurizio Sarri's side will be successful in their remaining matches, urging his team to win clashes against Bologna, Roma and Verona.
"We'll need to win all the remaining games to win the title because Napoli will win every remaining match. We need to take things game by game now," he said.
"About the match [against Inter], I'll say it was a wonderful match. It was tough, even though they played with 10 men after the 15th minute.
"The San Siro was incredible, playing in that stadium in front of 80,000 people is always astonishing.
"So, Italian football and sport won tonight. And fortunately Juventus also won."
Matias Vecino was sent off in the 18th minute for Inter, who led 2-1 with less than five minutes remaining.
But a Milan Skriniar own goal and Gonzalo Higuain strike saw Juve to a come-from-behind win.