Lazio reached the semi-finals of the Italian Cup on Wednesday after coming out on top of a fiery derby with Roma 1-0, a match which finished with three red cards.

Mattia Zaccagni's penalty five minutes after the break set up a two-legged semi-final clash with either Juventus or Frosinone, who play on Thursday, in April.

"We're proud of the result because we think that our performance deserved it," said Lazio owner Claudio Lotito to Mediaset.

"Today the team showed itself to be a united and determined group, that's what a football team needs to be."

Zaccagni's spot-kick decided a match which featured plenty of tension but little in the way of goalmouth action.

Rival fans launched flares at each other before and during the match while Roma midfielder Edoardo Bove was hit on the neck by a beer bottle after being substituted for Stephan El Shaarawy in the 76th minute.

On the pitch Matias Vecino forced a save from Rui Patricio shortly before Zaccagni's decisive spot-kick, which was given for a foul by Dean Huijsen on Valentin Castellanos.

And Vecino twice went close afterwards as Roma struggled to create chances despite having star attackers Paulo Dybala and Romelu Lukaku on the pitch.

Dybala had to leave the field at half-time and his replacement Lorenzo Pellegrini couldn't add any attacking inspiration for the hosts.

The best Jose Mourinho's men could muster was Andrea Belotti's 86th-minute half-volley which was well saved by Christos Mandas, who then did brilliantly to stop Lorenzo Pellegrini poking in on the rebound.

Lazio forward Pedro and his Roma counterpart Sardar Azmoun were both sent off in stoppage time as tempers flared, while Roma defender Gianluca Mancini was also dismissed for dissent after the final whistle.

"It's always painful to lose, doubly so in the derby," said Mourinho to Mediaset.

"It's a modern football penalty, the sort that wouldn't have been given before VAR. The referee didn't give it when he was three metres away but with VAR he then gives it."

Later AC Milan host Atalanta in the second of two quarter-finals on Wednesday, with the winner facing Fiorentina, who beat Bologna on Tuesday.