Rafael Leao scored the fastest goal in Serie A history on Sunday, netting after just six seconds to set leaders AC Milan on their way to a 2-1 win at Sassuolo.
Alexis Saelemaekers scored Milan's other goal as the Rossoneri remained a point clear of second-place Inter Milan, who beat promoted Spezia 2-1.
"Yes, it's not like we're brushing our dolls," Milan coach Stefano Pioli, when asked if they had prepared for the goal in training.
"We prepare ourselves, we study our opponents and we try things to put them in difficulty.
"Today it went well."
Roma missed the chance to move level with third-place Juventus as they lost 4-1 at Atalanta.
Lazio skipper Ciro Immobile produced a great headed goal and then set up Luis Alberto for their second as the hosts defeated fifth-placed Napoli 2-0.
Lazio are now eighth, sitting level on points with sixth-placed Sassuolo and seventh-placed Atalanta.
Milan were missing several top players, with a number of others joining star forward Zlatan Ibrahimovic in the treatment room.
However, the made the perfect start when Hakan Calhanoglu surged forward from the kick-off and threaded the ball through to Leao, who fired it into the net.
Statistics supplier Opta said the Portuguese youngster's goal beat the previous record of eight seconds set by Piacenza's Paolo Poggi against Fiorentina in 2001.
Milan later tweeted that Leao's goal was scored after precisely 6.2 seconds.
Saelemaekers doubled the lead in the 26th as he tapped in after being set up by Theo Hernandez.
Milan seemed to be heading for a comfortable win before Domenico Berardi's free kick was deflected in, a minute from time, to set up a nervy finale.
Achraf Hakimi and Romelu Lukaku helped Inter to a sixth successive league win.
After a goalless first half, Hakimi fired in a smart pass from Lautaro Martinez before Lukaku doubled Inter's lead from the penalty spot.
Substitute Roberto Piccoli netted a consolation for Spezia in stoppage time with his first Serie A goal.
Substitute Josip Ilicic provided two assists and scored a brilliant solo goal as Atalanta bounced back from Edin Dzeko's early opener for Roma.
A costly mistake from Bologna goalkeeper Angelo Da Costa helped relegation-threatened Torino to a 1-1 draw at home while second-bottom Genoa lost 2-0 at Benevento and Cagliari drew 1-1 with Udinese.