The 21-year-old Italy forward hit the post early on and scored twice in the first 18 minutes in Florence.

Aleksandar Kolarov netted for Roma before Luis Muriel made it 3-1 at half-time.

Chiesa completed his hat-trick in the second half, Giovanni Simeone got two and Marco Benassi also found the net.

Substitute Edin Dzeko was sent off for the visitors late on after arguing with the referee.

It was only the sixth time in the club's history that Roma had conceded seven goals. The last time was against Bayern Munich in 2014.

Stefano Pioli's Fiorentina will face Atalanta, who beat holders Juventus 3-0, in a two-legged semi-final.