A late goal from Senad Lulic gave Lazio a 1-0 victory over Napoli on Wednesday and a place in the Coppa Italia final against Juventus.
Lazio advanced 2-1 on aggregate and will seek their third title in the last seven years in the June 7 final at their home stadium.
In the 79th minute, Lulic was left unmarked to steer home a cross from Felipe Anderson from inside the box.
Napoli argued in vain that Lazio forward Miroslav Klose was offside at the start of the move.
The result will put more pressure on Napoli boss Rafael Benitez, whose side dominated for much of the game but could not find a breakthrough.
Lulic performed more heroics late on when he cleared a late effort off the line as Lazio held on to reach their eighth Coppa Italia final.
Juventus overcame a first-leg deficit with a 3-0 win at Fiorentina on Tuesday.
Information from the Press Association was used in this report