* Napoli beat Fiorentina 3-1 at Olympic Stadium
* Match overshadowed by shootings, fan clashes
* Winners finish with 10 men after Inler sent off (Adds quotes)
By Terry Daley
ROME, May 3 (Reuters) - Napoli beat Fiorentina 3-1 to win their fifth Italian Cup on Saturday in a match that kicked off 45 minutes late after three fans were shot, one critically, in an incident near Rome's Olympic Stadium.
A first half brace from Italy international Lorenzo Insigne and a late strike from Dries Mertens helped the southern side, who finished with 10 men, to their second Cup victory in three years.
Insigne's goals in the 11th and 17th minutes put Fiorentina on the back foot but Juan Vargas brought his side back into the game just before the half hour with a fantastic volley. Mertens then added Napoli's third in injury time.
Fiorentina took the game to their rivals in the second half, with Giuseppe Rossi making a first appearance since Jan. 5 as a 69th-minute substitute, but Napoli held on despite Gokhan Inler's 79th minute sending off.
"The most important thing tonight is the performance we saw on the pitch. We showed we wanted to win and went out and delivered," Napoli manager Rafa Benitez told reporters.
"It seemed at the start that everything was going to be easy for us. But Fiorentina are a strong side, they hit back and but it in the end it was a great result for us.
"The squad is strong, they want to win and I think this bodes well for us in the future," added the Spaniard.
"It was one of those games that could have ended in any number of ways," said Fiore coach Vincenzo Montella who felt the match was oversahdowed by the trouble ahead of the game.
"My biggest regret is not being able to enjoy the final as I should have been able to due to what happened before the match. I think that was the case for everyone."
The match had looked in danger of being cancelled as news of the shooting filtered through.
Police said in a statement that the incident did not appear to be linked to broader clashes in the Tor di Quinto area, with rival supporters throwing firecrackers and other objects at each other before the game.
A large section of the Napoli supporters watched the match in almost complete silence in protest.
As organisers and Napoli midfielder Marek Hamsik moved towards the fans to talk with hardcore 'ultra' leaders about whether the game should go ahead, they were pelted with flares and smoke bombs.
Piero Grasso, the president of Italy's Senate who was at the stadium to present the trophy at the end of the match, declared those responsible were "delinquents, not supporters.
"A game of football cannot be turned into a war between rival gangs," he said.
Despite the ugly atmosphere, it was a beautiful goal that opened the scoring with Hamsik bursting away on the break before slipping the ball to Insigne, who curled in his sixth goal of the season off the post.
He had his seventh only five minutes later, this time meeting Gonzalo Higuain's misplaced squared pass first time with a scuffed left foot strike that deflected off Nenad Tomovic and past Fiorentina keeper Noberto Neto.
Fiore looked shell-shocked but regrouped and got back into the game in the 28th minute thanks to a superb back-heeled flick on from Josip Ilicic which Vargas met with a thumping volley that flew past a motionless Pepe Reina.
The Tuscan side were unlucky not to go in level at the break after Alberto Aquilani volleyed home Ilicic's perfectly delivered free-kick a minute before halftime, only to see his effort ruled out for the tightest of offside decisions.
Rossi came on to a rousing reception from the Fiorentina fans and then, with Inler off, Ilicic squandered a perfect chance to take the final to extra time when he sliced wide after a superb pass from Alessandro Matri.
"It was right at the end in the 90th minute, it couldn't have been any more decisive," said Montella. "Reina did really well to close the angle down, but that is how football works."
Mertens made no mistake for Napoli, though, the Belgian international drilling home a smart left-foot finish to send the Naples fans wild with joy. Some also spilled on to the pitch to celebrate and taunt the Fiorentina supporters. (Reporting by Terry Daley, editing by Alan Baldwin)