Napoli dropped points ahead of the Champions League showdown against AC Milan following draw with Verona on Saturday, while Inter Milan were beaten 1-0 by Monza with Benfica looming.
Italy's champions-elect Napoli have had their imposing league lead cut to 14 points after a second-string XI could only manage a goalless stalemate with Verona and second-placed Lazio won at Spezia on Friday.
As it stands Luciano Spalletti's side still need 11 points from their final eight matches to seal their first league title since 1990, but all eyes are now on Tuesday's second leg of their quarter-final clash with Milan in Naples in which they have to overturn a 1-0 deficit.
Not even the second-half introduction of returning star striker Victor Osimhen -- who smashed a volley off the bar in the 82nd minute -- and Khvicha Kvaratskhelia could force a breakthrough at a loud Stadio Maradona.
Spalletti said that Serie A's top scorer Osimhen will start on Tuesday, adding: "He is a hero for these fans, there is always so much enthusiasm around him".
The draw was a fine result for struggling Verona which puts them three points behind Spezia, who sit just outside the drop zone.
Inter would have moved above both Milan and Roma had they beaten Monza but Luca Caldirola's 78th minute header condemned Simone Inzaghi's side to their 11 defeat of an immensely disppointing league season.
They are two points away from Italy's Champions League places, and risk not qualifying for the competition in which they should reach the last four on Wednesday.
Inter host Benfica hot favourites to be in an all-Italian semi-final thanks to their impressive 2-0 win in Lisbon last week, but have lost their last three home matches without scoring a single goal.