Rafael Leao scored twice and Brahim Diaz set up one goal and scored another to hand Napoli their heaviest defeat ROME: If this was just the antipasto, Napoli should be concerned about what AC Milan will serve up for the main course. In the first of three matchups between Milan and Napoli this month, the defending Serie A champion routed this season’s runaway leader 4-0 on Sunday ahead of two more clashes in the Champions League quarterfinals. Rafael Leao scored twice and Brahim Diaz set up one goal and scored another to hand Napoli their heaviest defeat of what otherwise has been an extraordinary season. “We’re happy with the performance but it’s just one game,” Milan coach Stefano Pioli said. “Tonight’s result has nothing to do with the Champions League games, because that’s a different competition. That will be a very balanced contest.” Napoli’s only other losses in the Italian league this season both came by scores of 1-0, to Inter Milan in January and to Lazio a month ago. Napoli were also beaten 2-0 by Liverpool in the final match of the Champions League group phase but that loss came after the Partenopei had already clinched a spot in the round of 16. Otherwise, Napoli’s only other defeat in 2022-23 came against Cremonese on penalties in the Italian Cup. Milan moved up to third place, 20 points behind Napoli and four points behind Lazio. Milan controlled from the start at the Diego Armando Maradona stadium and Diaz set up Milan’s early opener for Leão with a perfect through ball. Leao — last season’s MVP — then did the rest by chipping in over Napoli goalkeeper Alex Meret. Diaz produced some more fireworks when he faked out Mario Rui to score with a deflection from close range in the 25th. It marked the first time that Napoli conceded twice in the opening 25 minutes of a Serie A game since a match against Juventus in Aug. 2019. Leao fired in the third from a sharp angle near the hour mark after deceiving Napoli defender Amir Rrahmani. Then Alexis Saelemaekers weaved through Napoli’s defense less than 10 minutes later to complete the rout. At the final whistle, Leao exchanged shirts with his fellow left winger at Napoli, Khvicha Kvaratskhelia. “I’m a big fan of his,” Leao said. “I like what he does on the pitch. He’s similar to me, he tries to dribble by opponents.” Milan host Napoli at the San Siro in the first leg of the Champions League quarterfinals in 10 days, then Napoli host the second leg six days later. Napoli hope to have Serie A scoring leader Victor Osimhen back for those matches after its center forward was ruled out of this game due to an injured abductor muscle in his left leg. Lazio tightened their grip on second place with a 2-0 win at Silvio Berlusconi’s Monza. Having beaten Napoli and Roma in the derby before the international break, Lazio extended their unbeaten streak in the Italian league to six matches. A free kick from Sergej Milinkovic-Savic after the break followed an early goal from Pedro for Lazio. Lazio have kept six consecutive clean sheets for the second time this season. Georginio Wijnaldum scored one goal and earned a penalty that Paulo Dybala converted as Roma beat 10-man Sampdoria 3-0 to move level on points with fourth-place Inter Milan. All of the goals came after Sampdoria defender Jeison Murillo was sent off for two yellow cards early in the second half. Wijnaldum opened the scoring with a header then Stephan El Shaarawy sealed it from the edge of the area after Dybala’s penalty. Roma coach Jose Mourinho’s counterpart at Sampdoria, Dejan Stankovic, was one of Mourinho’s players when he coached Inter to a treble of titles in 2010. Also, Bologna continued to impress under Thiago Motta with a 3-0 win over Udinese to move up to eighth. Stefan Posch, Nikola Moro and Musa Barrow scored for Bologna. Motta replaced the fired Sinisa MiHajjlović in September after Bologna was unable to produce a win in itheir opening five matches. Salernitana drew 1-1 at Spezia.