Romelu Lukaku has had the last laugh - and a goal - in helping leaders Inter Milan beat Zlatan Ibrahimovic's AC Milan 3-0 in their biggest Serie A derby match in a decade.
The game took place almost a month after a heated spat between the star players in the Coppa Italia and once again it was Belgian striker Lukaku who was victorious.
He set up two-goal Lautaro Martinez for an early opener and then sealed the result in the 66th minute with Inter's third.
Martinez doubled his tally early in the second half during Milan's best spell of the match.
"Lukaku works a lot and always makes himself available for the team," Martinez said, praising his strike partner.
"He is a great person and a great player. We are happy to have him with us. I am convinced that he can still improve a lot."
Inter extended their advantage to four points over second-placed Milan, who had led the league for much of the season.
"It's been a difficult week but we'll get back on track," Milan coach Stefano Pioli said.
"If you told us a year ago, or even just three months ago, that at this point of the season we would be second, we would have leapt in the air with joy."
The last time Inter and Milan went into the Derby della Madonnina occupying the top two spots in the table was in 2011, when Milan were above Inter.
The Rossoneri won that match and went on to win the league title - the last team other than Juventus to do so.
There were no supporters in the San Siro because of coronavirus restrictions but thousands of fans from both sides gathered outside the stadium.
"We want to dedicate this win to our fans. The welcome they gave us at the stadium gave us goosebumps," Inter coach Antonio Conte said.
"Credit goes to the lads, they put in an extraordinary performance."
Elsewhere, Roma are third despite drawing 0-0 at 10-man Benevento.
The capital side are nine points adrift of Inter and one point above Atalanta, who beat Napoli 4-2 to move up to fourth.
Napoli slipped to seventh.
At the other end of the table, Udinese went 13th by fighting back from two goals down to draw 2-2 at second-bottom Parma.