Rafael Leao earned a place in the Serie A history books before he and Stefano Pioli confirmed Milan's breathtaking start at Sassuolo was cooked up on the training ground.
The Portuguese forward scored after just six seconds as the leaders stunned their hosts, with Milan going on to secure a 2-1 victory.
Brahim Diaz touched the ball from kick-off to Hakan Calhanoglu who charged through lines of Sassuolo players before feeding Leao, who sprinted in from the left.
Leao took two touches as he entered the penalty area before driving a powerful shot beyond Andrea Consigli, with head coach Pioli revealing it was among a handful of ploys Milan had prepared.
Pioli told Sky Sport Italia: "Let's say we have four or five kick-off situations and every now and then we alternate them.
"We wanted to approach the match well, in the last few matches we had been lacking a little bit. it was good from Calhanoglu and Leao."
Leao himself said, according to La Gazzetta Dello Sport: "Yes, we had prepared it in training. But we are Milan, this match was important for us because we had lost points in the previous matches."
Back-to-back 2-2 draws against Parma and Genoa had seen Milan lose some of their early-season momentum, and news of an injury setback for Zlatan Ibrahimovic on the eve of the Sassuolo game came as a fresh blow.
But Pioli had Milan fired up for this game, and they showed urgency from the first whistle.
"There are times when matches are worth a little more," Pioli said. "We weren't happy with the draws. Today it was very important from a mental point of view. Being able to win gives us great satisfaction."
Milan have now scored two or more goals in 15 consecutive Serie A games, the most times that has been achieved in succession in the top-five European leagues since Barcelona did so 18 times in a row in 1948.
Leao had faced pre-match criticism from Pioli over his recent performances, but the coach was smiling as the 21-year-old beat the previous fastest goal on record in Serie A - Paolo Poggi for Piacenza against Fiorentina in 2001.
A booking for Franck Kessie was his fifth in Serie A this season and triggers a suspension that means he will miss the game with Lazio at San Siro on Wednesday.
That presents Pioli with another selection issue, and the head coach would welcome additions to his squad in the January transfer market as Milan look to push for a first Scudetto since the 2010-11 season.
"If there are the right opportunities to improve the staff we will do it, otherwise we will stay like this," Pioli said. "The squad is compact and united, so it is difficult to manage so many absences."