Milan - Diego Maradona offered glowing praise as Napoli boosted their hopes of a first Serie A title since 1990 by going two points clear of champions Juventus and Inter Milan.
The last time Napoli were top of the table at the halfway stage of the season in Italy was 26 years ago, when Maradona led the 'Partenopei' to the second of their two leagues titles in 1990.
But Fiorentina's shock 3-1 defeat to Lazio on Saturday whet Napoli's appetite, and it grew considerably earlier Sunday when Inter suffered a shock 1-0 defeat to Sassuolo at the San Siro.
Napoli pounced on those setbacks to hammer league new boys Frosinone in a one-sided encounter that saw Gonzalo Higuain hit a brace, including one from the spot, to take his goals tally to 18 goals from 19 games.
Sarri has consistently played down Napoli's title hopes and has every reason after Juventus beat Sampdoria 2-1 in Genoa to claim their ninth victory on the trot to move two places up to second.
Paul Pogba broke the deadlock on 17 minutes with an angled strike and Sami Khedira found himself in acres of space to double the champions' lead on 46 minutes before Antonio Cassano hit a consolation just after the hour.
Inter dropped to third due to inferior goal difference, while Fiorentina are in fourth place at three points behind and Roma are seven points off the pace in fifth after being held 1-1 by AC Milan on Saturday.
Only four months ago Maradona publicly embarrassed Napoli coach Maurizio Sarri following an inauspicious start to the campaign.
On that occasion Sarri, a lifelong Napoli and Maradona fan, soaked up the criticism and on Sunday it was time for payback.
"It's with great joy that I heard about Napoli's result, which we've all been waiting on for many years," said Maradona in a message sent to Sky Sport Italia.
"Knowing that the city of Naples and my Neapolitan fans can enjoy such emotion makes me even more happy for them. Go on Napoli. Now I want us to win the league title."
Against a Frosinone side fighting for top flight survival, Napoli took a 20th minute lead when Raul Albiol coolly flicked a volley into the net at the back post following a corner.
Higuain doubled Napoli's lead from the penalty spot on the half-hour and claimed his second in two crazy, second-half minutes that saw captain Marek Hamsik on target.
Frosinone's defence backed off as Hamsik ran towards the edge of the area before unleashing a drive that beat Massimo Zappino down low in the 59th minute.
Barely 60 seconds later, Higuain muscled his way through two defenders to beat Zappino down low as the 'keeper came rushing out to block.
The goals took the Argentinian's tally to 18 from 19 games, an impressive return given the league's 'Capocannoniere' (top scorer) award has been won the past two seasons with 22 goals.
Sarri replaced Higuain with Manolo Gabbiadini 20 minutes into the second half, and six minutes later the striker hit Napoli's fifth, a superb curling effort that sneaked into the far top corner.
Napoli looked to be heading for their second 5-0 win of the season having routed Lazio by the same scoreline in September, but with nine minutes remaining Paolo Sammarco swung at a short pass on the right side of the area to beat visiting 'keeper Pepe Reina with an angled drive.
Sarri, who celebrated his 57th birthday on Sunday, was quick to underline the persistent threat of Juventus.
"They've won four titles in four years, so you could say they've got something extra we don't," he said.
"I'm the only one who's been consistent in saying that, even when Juve were down near the bottom of the table, they would come fighting back with a series of wins and that's what they're doing."