AC Milan moved up to third in Serie A after Sunday's 2-0 win over Atalanta, drawing level on points with Inter Milan, who fell further behind runaway leaders Napoli with a 1-0 defeat at Bologna.
Stefano Pioli's side are five points ahead of fifth-placed Lazio in the race for the Champions League thanks in part to Theo Hernandez's volley crashing off the post and into the goal via Juan Musso's back in the 26th minute.
A late dinked finish from Junior Messias at a soaking San Siro ensured Milan had their third league victory in a row.
"I'm counting the goal as mine. Oli (Giroud) did well to knock it down for me, I think it was a good goal," said Hernandez to DAZN.
Milan could have had more in the second half of a underwhelming encounter, Rafael Leo and Messias both wasting golden chances from close range before the latter sealed the points from Leao's pass with four minutes remaining.
The hosts were also cheered by the return of France goalkeeper Mike Maignan after five months out and Zlatan Ibrahimovic, who came on as a second-half substitute.
Veteran forward Ibrahimovic had been sidelined since May last year after having the anterior cruciate ligament in his left knee reconstructed.
"Mike and Zlatan aren't only great players, they're leaders with so much experience and having them available makes a big difference," said Pioli.
Atalanta stay sixth, three points behind Roma in fourth who can join Milan and Inter on 47 points with a win at bottom side Cremonese on Tuesday.
Gian Piero Gasperini's side cannot complain about the result as they didn't trouble Maignan once and have now lost three of their last four league matches.
The Milan giants are a whopping 18 points behind Napoli after Bologna beat Inter 1-0 in Sunday's early match.
Orsolini sinks Inter
Riccardo Orsolini lashed home the only goal of the game in the 76th minute at the Stadio Dall'Ara to move Bologna up to seventh and edge Napoli even closer to their first league title since 1990.
Second-placed Inter had the chance to move back to within 15 points of Napoli, who beat Empoli 2-0 on Saturday, with a win.
But Simone Inzaghi's side looked drained after Wednesday's Champions League last 16, first leg victory over Porto.
"We don't seem able to maintain the same levels of concentration when we play every two or so days," Inzaghi said.
"We have a packed fixture list and we used up a lot of energy against Porto on Wednesday, but we should still be doing better."
Without star striker Marko Arnautovic, Thiago Motta's Bologna also had a Musa Barrow goal disallowed for offside and struck the bar through Roberto Soriano in the first half.
Orsolini's winner was his seventh in Serie A this season, the Italian international pushing Bologna towards the European qualification places by scoring four times and adding assists in his last five matches.
Bologna also moved above Juventus who are hoping for a fourth straight league win against local rivals Torino on Tuesday after crushing Nantes to reach the last 16 of the Europa League in midweek.
M'Bala Nzola scored twice in his first start in a month in Spezia's 2-2 draw at Udinese which boosted his team's battle against relegation.
Angola forward Nzola is now on 11 league strikes for the season after putting Spezia ahead in the sixth minute and then levelling the scores with a neat finish in the 72nd minute.
The 26-year-old had been out with a calf injury before returning as a substitute against Juventus last weekend.
Spezia are 17th, three points ahead of Verona who are just inside the relegation zone and host Fiorentina on Monday.
Four points ahead of Spezia are Salernitana who hammered Monza 3-0 in Sunday's only afternoon match.
