The hosts took an early lead through Antonio Candreva's strike that caught out Napoli goalkeeper Morgan De Sanctis, before Napoli levelled when Goran Pandev scored against his former club with an accomplished finish.
But the game will be remembered for Lazio's second, an explosive bicycle kick by Stefano Mauri that will go down as one of the goals of the season.
Cristian Ledesma added a third from the penalty spot as Lazio tightened their grip on third place, leaving Napoli six points off third place in fifth.
Lazio fans paid their respects to recently deceased club legend Giorgio Chinaglia, who played over 200 times in seven years for the Biancazzurri, with a minute’s silence before kick-off.
And, on an emotional night inside the stadium, the home fans didn’t have to wait long to celebrate the opener - which came courtesy of an error by Napoli keeper De Sanctis.
Abdoulay Konko created the chance with a ball into the feet of Tommaso Rocchi, who teed up Candreva to fire a powerful low effort that squeezed under the body of De Sanctis, who should have kept it out.
Napoli have shown throughout recent seasons that their favoured form of defence is attack, and they created a chance that Edinson Cavani would usually bury, but this time he was denied by a superb stop by Federico Marchetti, who was quick off his line to smother the Uruguayan's goalbound effort.
But Napoli continued to push forward in numbers with their forwards linking to great effect. And the visitors were eventually rewarded when Ezequiel Lavezzi caught out the Lazio defence with a backheel that wrong-footed defender Lorik Cana, allowing Pandev to sneak in and finish well against his former employers.
A frantic first half came to a controversial climax as Pandev appeared to be bodychecked to the ground by Cana – but the referee made a huge call in rejecting what looked to be a legitimate penalty claim.
Undeterred, Napoli made a strong start to the second half and could have led when Lavezzi flashed a dangerous low ball into the six yard area, but Pandev couldn't make the contact required to steer in what would have been a certain goal.
Napoli kept themselves in the game with some desperate defending but were undone by a moment of sheer brilliance by Mauri.
Stefan Radu picked out Mauri with a cross from the left and the former Udinese man met it with a spectacular overhead kick that saw the ball rifle past De Sanctis and into the roof of the net.
It was a stunning strike worthy of winning any game but Napoli were unlucky to be denied a good goal moments later, when Marek Hamsik's effort was chalked off for offside against Cavani, who was wrongly adjudged to be offside in the build-up.
Lazio sealed the win with Ledesma's unstoppable penalty late on after Miguel Britos had tripped Rocchi following a poor pass by Gokhan Inler.
The win was greeted by a deafening roar from the home support - as Lazio's victory represents a crucial win and a fitting tribute to their legendary striker Chinaglia.