Zlatan Ibrahimovic clashed with former Manchester United team-mate Romelu Lukaku during a heated Milan derby in the Italian Cup quarter-finals on Tuesday.
AC Milan's Ibrahimovic and Inter's Lukaku were both booked following a spat at the end of the first half, which continued into the tunnel during the interval.
The pair could be seen - and heard on television due to the San Siro being empty - exchanging insults as Lukaku had to be restrained by his team-mates as he attempted to confront the Swedish forward.
Ibrahimovic, who had given Milan a first-half lead, was sent off after picking up a second yellow card after the break, while Lukaku levelled with a penalty before Christian Eriksen struck a stoppage-time winner for Inter to send them through with a 2-1 win.
Ibrahimovic and Lukaku spent the 2017-18 season as team-mates at Old Trafford, with the Belgian having previously said he was able to learn from his fellow striker during that period.
However, there appeared to be a lack of goodwill between the pair as what started as an exchange of words led to the pair going head to head.
The Coppa Italia clash came with the sides also fighting at the top of the Serie A table, with AC Milan two points clear of second-placed Inter at the halfway stage of the season.
The other three quarter-final ties are to follow on Wednesday and Thursday, with fellow Serie A title contenders Juventus, Napoli, Atalanta and Lazio all still in the competition.
Lukaku vs Ibra: A clash between kings
Lukaku and Ibrahimovic's encounter at the San Siro was the latest chapter in their running saga which began when the two were team-mates at Old Trafford.
Lukaku said in an interview with Tiki Taka ahead of their first encounter in Serie A: "Ibra is a champion, I respect him. In Manchester I could train every day with him, that was the most beautiful thing for me. It will be nice to play against him. He is a great champion and professional.
"For me it's not normal that he can do those things at his age. He works a lot; he always gave me advice when we played together in Manchester."
But in an interview with La Gazzetta dello Sport in 2019, the 39-year-old Swede was far from complimentary when discussing Lukaku's technique and said he made a bet with the forward while the pair were together at United - which was turned down.
"I will say this on Romelu: don't expect good technique from Lukaku. His best strength is sheer power. If only he'd listened to me," Ibrahimovic said.
"At Manchester United, we made a bet: 'I'll give you £50 for every decent first touch you make'.
"He replied: 'What do I win if I get them all right?' I told him nothing, he would simply become a better player. For the record, he never accepted the bet! Perhaps he was afraid of losing?! Joking aside, Lukaku has this mad hunger to prove himself to the world and I'm sure he will do well at Inter too."
Back in February 2020, Lukaku scored in the final minute to complete a 4-2 win over Milan and he posted on social media a "new king" was in town, inferring he had dethroned Ibrahimovic in the Italian city.
Ibrahimovic and Milan had previously stated the Swede's second spell with the Rossoneri marked the "return of the king".
Spain: Finalists Real Sociedad knocked out
Real Betis knocked last year's Copa del Rey finalists Real Sociedad out with a 3-1 win thanks to two extra-time goals from Borja Iglesias in their last-16 clash on Tuesday after both sides had a man sent off.
Betis striker Iglesias scored in either half during the extra period to send the home side into the quarter-finals, after Sergio Canales' 79th-minute equaliser cancelled out Sociedad forward Mikel Oyarzabal's early opener.
Sociedad had midfielder Asier Illarramendi sent off early in the second half in only his second match since returning from a 17-month injury layoff, while Betis forward Antonio Sanabria was also dismissed in the 76th minute also for a second booking.
Sociedad's Adnan Januzaj looked to have scored a late goal in extra time which would have set up an interesting finale but the effort was ruled out for offside after a VAR review.
The Basque side could still lift the Copa del Rey, however, as they play last year's rescheduled final against Athletic Bilbao in April after the match was postponed due to the novel coronavirus pandemic.
Elsewhere, Villarreal beat second division Girona 1-0, while Levante won 4-2 at Real Valladolid to also advance.