AC Milan maintained its lead in Serie A after beating relegation-threatened Genoa 2-0.
Rafael Leão and Junior Messias helped Milan move back two points ahead of Inter after the defending champion won at Spezia 3-1 hours earlier on Friday.
Inter has played a match less than Milan as it still has to play a postponed match against Bologna.
The two Milan teams also meet on Tuesday in the second leg of the Italian Cup semifinals.
Genoa remained three points from safety.
Milan was again going through an injury crisis and struggling for goals ahead of the match against Genoa. It went in on the back of two straight goalless draws and only scoring four goals in its last seven matches.
Veteran forward Zlatan Ibrahimovic was out with a knee problem, the latest in a series of injuries this season.
Milan took the lead in the 11th minute when Pierre Kalulu put in a tantalising cross from the right to the back post where Leão volleyed into the bottom far corner.
The Rossoneri had few more real goal-scoring opportunities but should have doubled their lead in the 57th when Olivier Giroud fired a cross from Alexis Saelemaekers over the bar from close range.
Milan sealed the result three minutes from time. Genoa goalkeeper Salvatore Sirigu parried Messias' initial shot with a brilliant one-handed save but the Rossoneri forward fired in the rebound.
Substitute Lautaro Martínez returned from suspension to score one goal and set up another as Inter kept up the pressure on its city rival.
The Nerazzurri struggled to get going on a balmy day in Spezia and almost conceded early but Inter goalkeeper Samir Handanovic rushed off his line and grabbed the ball following a wayward interception from teammate Ivan Perisic.
Inter broke the deadlock in the 31st with its first shot on goal. Marcelo Brozovic started and finished the move as he chipped a pass into the area to Danilo D'Ambrosio, who nodded it back for the Croatia midfielder to drive into the top left corner.
Martínez, who missed last weekend's win over Hellas Verona due to suspension, came off the bench on the hour mark and doubled his side's lead 13 minutes later.
Perisic ran onto a cross-field pass to the left flank and cut inside before whipping in a low cross which Martínez flicked into the far corner with his back to goal.
Spezia captain Giulio Maggiore set up a nervy finale when he halved the deficit with a fine strike into the top left corner in the 88th minute, but Alexis Sánchez secured the result in stoppage time.
The referee waved play on after a foul on Sánchez and the Inter forward got back up to fire a Martínez assist into the bottom left corner.
There was a somewhat bizarre incident involving Spezia forward M'Bala Nzola. He came on in the 60th but the referee spotted his large earring and ordered him to remove it. Nzola spent several minutes fiddling with it on the touchline, aided by Spezia staff, but couldn't remove it and had to be substituted, 10 minutes after coming onto the field.