Ronaldo received a player-of-the-month award before kick-off and continued his good recent form with the opening goal, becoming the first player to score 400 goals in Europe's top-five leagues in the process.
Higuain told Gazzetta dello Sport in an interview published yesterday that he felt something was amiss when he was left on the bench for the Coppa Italia final against AC Milan in May.
"On another day we could have scored a third goal, but it wasn't meant to be". These are situations that shouldn't happen. We had to win.
When asked whether there's no love lost between him and Juventus, Higuain said that he has a feeling of affection for the club because they treated him very well. "We went from frantic to sleeping and vice versa".
But Daniel Bessa equalised with a header from Christian Kouame's cross.
Allegri hopes the lack of concentration will serve as a warning going forward.
He added: "We have to take the positives from the game and I think the way we played in the second half especially, we were fantastic at times".
"A good 10 minutes before the goal, we were already drifting out of the game", he said. Everyone will now remember that nothing can be taken for granted.
"We have to go into the game looking to start on more of the front foot, especially at home".
The result gives Napoli the chance to close to within four points of Juve at the top of the table and sees their 11-game winning run in all competitive competitions come to an end just three days before they face Manchester United in the Champions League.