Two second-half goals from Mario Gomez couldn't secure victory as Fiorentina drew 2-2 at Udinese.
Wolfsburg and Napoli meet for the first time in their history as the stand-out tie in the Europa League quarter-finals.
Roma fell to their first defeat in Serie A since November 1 as they suffered a surprise 2-0 home defeat to Sampdoria.
Fiorentina came from behind to pile the misery for AC Milan with a 2-1 win at the Stadio Artemio Franchi.
Wolfsburg, holders Sevilla and Napoli look on course for the Europa League quarter-finals after last-16 victories.
Paul Pogba's late goal gave Juventus a 1-0 win over Sassuolo to send them 11 points clear in Serie A.
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