Roma beat Juve to reach cup semis
The in-form Montenegro forward picked up the ball on the side of the area midway through the second half and effortlessly curled it into the far corner.
Rodrigo Taddei added a second goal in added time with an acrobatic finish to ensure Roma progressed to meet holders Inter Milan in the last four.
The bad-tempered encounter was riddled with fouls and injuries but Claudio Ranieri's side just about deserved to beat his former club with Simplicio also having a header saved.
Juve piled on the pressure towards the end but never really came close to scoring despite fielding a strong side as they became the latest big club to play their top players in a previously unloved competition.
Roma will play Inter in April and May's two-legged semi-finals after Leonardo's side beat Napoli on penalties on Wednesday.
Serie A leaders AC Milan take on Palermo in the other semi after the pair got past Sampdoria and Parma respectively earlier this week.