Seats and flares were thrown onto the pitch by Palermo fans and play was halted temporarily once in each half.
Italy international Candreva ran past a flare seconds before it exploded during Lazio's 3-0 win.
There had earlier been clashes between fans outside the stadium in Sicily.
Palermo are battling to avoid relegation to Italy's second division and, following a brawl outside the ground before the game, Palermo fans reacted angrily to their team going 2-0 down in the first 15 minutes.
They began lighting and throwing flares on to the pitch, with firecrackers setting explosions echoing throughout the stadium and prompting referee Andrea Gervasoni to halt the game for two minutes in the 24th minute.
When flares began to land on the pitch again after the interval, including the one that exploded metres away from Candreva, Gervasoni stopped the match again.
Discussions were held with officials and players before the game resumed after a five-minute stoppage.
Lazio's Serie A game at Palermo was halted twice because of crowd trouble, while visiting midfielder Antonio Candreva narrowly avoided an exploding flare.