Massimiliano Allegri demanded Juventus maintain their stunning momentum after opening up a four-point lead from Napoli at the top of the Serie A table.
A 2-0 defeat of Atalanta in Juve's game in hand over Napoli was their 12th straight win in Serie A, the last nine of which have come with clean sheets.
But although Juventus have taken charge of the Serie A title race with 10 rounds remaining, Allegri thinks there is still more to come from his side.
"We must not start thinking the Scudetto is suddenly in the bag," Allegri said.
"It's a decisive stage of the season but we must take things one step at a time, keep our heads and replenish our mental energy. You have to keep raising the bar in every game.
"Napoli are right up there behind us and we need lots of points to win the title.
"Now we have to play SPAL and it's never easy to win in Ferrara. We're expecting a real battle."
Higuain opened the scoring for Juve and set up Blaise Matuidi for the second goal as Allegri's men cruised to yet another victory.
"Gonzalo's really high on confidence at the moment and he's started setting up his team-mates now," Allegri said of the Argentina striker.
"[Paulo] Dybala's fitness is improving and the whole team is on the up from a physical point of view.
"The good thing is we made five or six change to the side on Sunday [a 2-0 win against Udinese] and we did the same again today but the result didn't change. We want to go all the way together."
Matuidi's goal was the first time the France international has scored in a home game for Juventus, but he was quick to give credit to Higuain.
"It was fantastic to score in front of our fans and celebrate with them after a hard week's work!" Matuidi said.
"I have Gonzalo to thank for his incredible assist leading to my goal, so thank you Pipita!
"We're now focusing on Saturday's match against SPAL. Of course, it's great to have this healthy lead over Napoli right now.
"I don't know how many points we'll have in the end. The most important thing is winning and that won't be easy because Napoli will not be giving up without a fight."