Inter Milan captain Mauro Icardi kept his cool, converting a 90th-minute penalty, to secure his hat-trick and a thrilling 3-2 win for his team over city rivals AC Milan at the San Siro.
"I don't know if I will sleep with the matchball tonight, as usually I can't sleep after games," Icardi told the Inter website. "Whatever happens I will keep it close because it is now a unqiue possession. It's a special thing to score a hat-trick in a derby."
Inter coach Luciano Spalletti described Icardi as a player "complete for his age."
'He was fundamental, he helped the team as he went to recover the ball, lessening the burden on his teammates," said Spalletti. "Then, he made no mistakes in attacking space in the box or with his finishing."
The spot-kick was controversially awarded, however, with defender Ricardo Rodriguez harshly adjudged to have fouled Danilo D'Ambrosio following a corner.
Before a capacity crowd, AC Milan had twice come from behind through Suso and a Samir Handanovic own goal and were moments away from a draw before Icardi scored at the death.
"Ricardo did not pull him down and D'Ambrosio has been very clever," Milan boss Vincenzo Montella told reporters.
"It makes me angry to lose like that. I hope we get a penalty like that in our next game. But I'm optimistic. For me the glass is half-full."
Defeat -- Milan's fourth in eight league games -- heaps more pressure on Montella after the club was expected to be challenging for the title following a $265 million spending spree on players in the summer.
Milan are now 10th in the league -- 10 points behind Inter, who are second, two points behind leader Napoli.
A rare home defeat for Juve
Pace-setters Napoli maintained their fine start to the season with a 1-0 win at Roma courtesy of Lorenzo Insigne's 20th-minute winner.
Third in Serie A are Juventus who suffered a first home defeat in more than two years as Lazio came from behind to beat the defending champions 2-1 at the Allianz Stadium.
Juve academy product Ciro Immobile scored twice, taking his Serie A tally to 11 goals in eight games, to inflict a first league loss since August 2015 on the Bianconeri, with substitute Paulo Dybala missing a stoppage-time penalty for the Turin side.
On Saturday, Napoli host Inter in a game that could enable the Serie A leaders to move five points clear of Spalletti's team.
Hertha Berlin take the knee
Bundesliga side Hertha Berlin took the knee before their league match against Schalke on Saturday, a match they went on to lose 2-0.
Hertha players linked arms and knelt on the pitch, while coaching staff, officials and substitutes took a knee off it.
In recent weeks NFL players have been choosing to sit or kneel during the US National Anthem, a protest which began last year when then-San Francisco 49ers quarterback Colin Kaepernick refused to stand for "The Star-Spangled Banner" in protest of racial and social injustice.
The NFL protest has come under great focus after US President Donald Trump said at a campaign-style rally in September: "Wouldn't you love to see one of these NFL owners, when somebody disrespects our flag, to say, 'Get that son of a bitch off the field right now, out, he's fired. He's fired."
The Bundesliga club posted on Twitter: "Hertha BSC stands for tolerance and responsibility! For a tolerant Berlin and an open-minded world, now and forevermore!"