The victory books Lazio a ticket to next season's Europa League, much-needed for Simone Inzaghi's side
Caicedo opened the scoring in the third minute with a smart finish after beating Omar Colley and made it two in 16 minutes later with a deft header from Romulo's cross.
Lazio's Italian Cup semifinal victory at AC Milan was overshadowed by continued racist abuse directed at Milan players Tiemoue Bakayoko and Franck Kessie.
The flash mob came a day before Italy's Liberation Day, celebrating the end of Nazi occupation, and ahead of a match in Milan already marked by tension.
Milan remain fourth on 56 points but Roma are two points behind in fifth before they play third-placed Inter Milan at the San Siro later on Saturday.
Victory at the Stadio Olimpico for Lazio also pulled them within six points of fourth-placed Inter.
Two Spanish fans and an American were hurt in the fight, which broke out ahead of Thursday's UEFA Europa League match, La Repubblica daily said.
Juventus had trailed after an Emre Can own-goal after an hour before substitute Joao Cancelo pulled the champions level and then earned the penalty which Ronaldo slotted in.
Napoli have 47 points from 20 games and are now seven ahead of third-placed Inter Milan who were held to a goalless draw at home by Sassuolo on Saturday.
The 51-year-old, who has struggled with alcoholism since he retired from top-flight football, was arrested at Durham station in northeast England on August 20.
Immobile scored his first-ever goal against Fiorentina to send Lazio third in Serie A with a 1-0 win at the Stadio Olimpico on Sunday.
Serbia's former coach Slavoljub Muslin paid with his job for failing to select Milinkovic-Slavic for the national side.
Late goals from captain Mauro Icardi and Matias Vecino ensured Inter return to Europe for the first time since the 2011-2012 season, along with Juventus, Napoli and Roma.
Serie-A: Juventus snowed off, Lazio go third as AC Milan register first away win against Roma in six years
Ciro Immobile and Sergej Milinkovic-Savic continued their goal-scoring sprees to lift Lazio into third, as Patrick Cutrone and Davide Calabria gave AC Milan victory.
Laxalt's late winner moved former Italian giants Genoa seven points clear of the relegation places while preventing third-placed Lazio from further consolidating a Champions League qualification spot.