Parma delivers blow to Lazio's CL hopes
Sergio Floccari scored twice for Roberto Donadoni's side after McDonald Mariga had given them an early lead.
Lionel Scaloni netted Lazio's goal in a defeat which gives Napoli and Udinese the chance to catch them in third place on Sunday.
Parma leap above Cagliari, Genoa, Fiorentina and Siena with an eight-point cushion over the relegation zone.
Only five minutes had been played when Mariga put the home side in front.
He was on hand to convert the rebound after Floccari's shot was saved well by Federico Marchetti.
Floccari added a second seven minutes later when the tricky Sebastian Giovinco's corner was fumbled by Marchetti and Gabriel Paletta's shot was diverted in by the head of Floccari.
Things went from bad to worse for Lazio when they lost Andre Dias with an injury in the 17th minute.
Giovinco could have finished the Biancoceleste off in the 32nd minute, but he shot wide after reaching Daniele Galloppa's long ball forwards.
Lazio reduced the arrears five minutes later when Scaloni, who had replaced Dias earlier, shot from long range and the ball took a deflection off Massimo Gobbi to beat Antonio Mirante in the Parma goal.
After the lights at the Tardini had gone off for a short period in the 63rd minute, Parma added a third goal with 19 minutes later to seal the win.
Floccari again pounced on a Giovinco set-piece, this time sending the Italy international's free-kick over the line from close range.
Parma had chances to win more comfortably with both Giovinco and Floccari going close, but the job was done with a precious win earning them a bit of breathing space in the bottom half of the table.