Inter Milan's hopes of qualifying for the Champions League were left hanging in the balance after they slumped to an embarrassing 4-1 defeat at Napoli in Serie A on Sunday.
Inter, who would have clinched a place in Europe's elite club competition with a victory, must now win their final game at home to Empoli, who are fighting relegation and have won their last three games, to guarantee a top-four finish.
Fabian Ruiz scored twice for Napoli -- already sure of finishing second -- after Piotr Zielinski and Dries Mertens set them on their way, while home defender Kalidou Koulibaly made a remarkable goal-line clearance from Lautaro Martinez.
With one game left, Inter dropped to fourth with 66 points, behind Atalanta, who drew 1-1 at champions Juventus, on the head-to-head record. AC Milan are a point behind in fifth after their 2-0 win over Frosinone.
"We need to keep clear heads. It was an bad performance but our destiny is in our own hands," said Inter coach Luciano Spalletti. "There is nothing wrong with losing to Napoli, but not in this way. The next game will be a final.
"We started well but we made mistakes in building moves from the back, which is how their first goal came about, and after that, our passing was all over the place."
Zielinski fired Napoli in front with a rasping drive in the 16th minute and Mertens ghosted in behind the Inter defence to head in Jose Callejon's cross in the 61st, the Belgian's 15th league goal of the season.
Koulibaly then denied Inter by somehow heading Martinez's powerful drive off the line from right underneath the crossbar.
Ruiz scored twice on the break to finish off the visitors, while Martinez hit the bar in between.
Icardi won and converted a soft penalty for Inter in the 81st but it was far too late for Luciano Spalletti's side.
Atalanta on brink of Champions League spot after Juventus draw
Josip Ilicic profited from some dozy defending to tap in the opener for the visitors during the first half, but Juve substitute Mario Mandzukic equalised with 10 minutes remaining.
The victory elevated the Bergamo side to third, level on 66 points with Inter Milan but ahead on head-to-head record.
Gian Piero Gasperini’s side will be assured of a top four finish if they beat Sassuolo in their final game of the season next weekend.
“It’s a positive result,” Gasperini told Sky Italia.
“Now we need to reach the finish line, so much work has been done and now we must go for it against Sassuolo. We still need to give everything."
Juventus, who clinched an eighth successive Serie A title almost a month ago, announced this week that Allegri would leave the club at the end of the season.
The home crowd bid farewell to the coach after five trophy-laden years, while veteran defender Andrea Barzagli also took to the Allianz Stadium pitch for the final time.
Juventus's form has dipped dramatically since they secured the title and they have now gone four league matches without a win for the first time since 2012.
Cristiano Ronaldo squandered a chance early on by blasting over the bar from a good position and they were made to rue that miss when Ilicic tapped in Atalanta’s 100th goal of the season in all competitions after 33 minutes.
Barzagli, who will be retiring after more than eight years at the club, was given a guard of honour by his team mates before the game and that was followed by a standing ovation when he was substituted in the second half.
Juve drew level when Mandzukic slid in to meet Juan Cuadrado’s looping cross at the back post and struck the ball into the net through Pierluigi Gollini’s legs.
The hosts were reduced to 10 men in stoppage time when Federico Bernardeschi was sent off for a rash challenge.
Galatasaray win 22nd Turkish title after beating closest rival
Defending Turkish champions Galatasaray won the title for the second season in a row on Sunday after defeating second placed Basaksehir 2-1 at home, with one game to play before the season ends.
Basaksehir made a better start to the game and scored in the 20th minute, but that only served to fire up Galatasaray fans and players.
Galatasaray scored twice in the second half, with Sofiane Feghouli and Henry Onyekuru's goals helping the club secure its 22nd Super Lig title.
The two Istanbul sides were locked on 66 points with two matches to play coming into Sunday's showdown.
But as the head-to-head record, rather than goal difference, is the deciding factor in Turkey between teams on equal points, the winner of the derby would win the title.
The two sides had drawn 1-1 in the first half of the season, so Sunday's win meant Galatasaray clinched the title even if they lost the last match of the season next week.
Anderlecht miss out on Europe ahead of Kompany arrival
Anderlecht missed out on European qualification for the first time in 56 years on Sunday, dealing a blow to Vincent Kompany who will take over as player-manager next season after leaving English treble winners ManchesterCity.
In the final series of playoff matches, the Brussels-based side lost 2-1 at AA Ghent, leaving them bottom of their six-team group after one win in 10 games.
Belgium defender Kompany said earlier on Sunday he would be joining Anderlecht after helping Premier League champions City with the FA Cup on Saturday to become the first team to win the English domestic treble, including the League Cup.
The 33-year-old will arrive at Anderlecht knowing he has work to do at a club that have won a record 34 Belgian league titles, but have underperformed this season and parted company with manager Fred Rutten a month ago.
Angry Anderlecht fans threw flares and smoke bombs onto the pitch during a match at arch-rivals Standard Liege in April, leaving the club with a fine and an order to play one game behind closed doors.
Following Sunday's final playoff round, champions Racing Genk will enter the Champions League group stage with runners-up Club Bruges in the qualifying phase. Third-placed Standard Liege will be in the Europa League qualifying round, while FC Antwerp and Ghent are still in the running for a possible berth.