Edy Reja's men endured an unexpected collapse early on, conceding twice in the opening quarter of an hour, and ultimately succumbed to a disappointing lossLazio were dealt a tough blow in their quest for a Champions League spot as they were stunned 3-1 by Parma at the Ennio Tardini.
McDonald Mariga opened the scoring early on and Sergio Floccari added another strike shortly after as the Biancocelesti were left reeling after just 12 minutes.
Substitute Lionel Scaloni, who replaced the injured Andre Dias midway through the first period, pulled one back for Lazio before the break, but it proved to be only a consolation as Floccari completed his brace against his former club in the second half.
The Gialloblu got off to an outstanding start as in the sixth minute Mariga stunned the visitors with a well-placed finish from inside the box. A cross by Sebastian Giovinco from the left found Floccari, whose header was cleared into the path of the Kenyan, who made no mistake.
Just as Lazio thought things could not get any worse, a fortunate turn of events saw Parma double their lead. A stray volley by Gabriel Paletta reached Floccari in the right place at the right time, and the former Genoa and Atalanta man powered a header past Federico Marchetti.
Things went from bad to worse for the Biancocelesti in the 17th minute when Andre Dias was forced to leave the pitch after sustaining an injury and was replaced by Argentine defender Scaloni.
Lazio tried to respond in the following minutes and had a great chance to pull one back after a cross by Cristian Ledesma reached Stefano Mauri in the centre of the box, but the former Udinese player missed to the left with his diving header.
Parma, however, were soon back in the ascendancy and on the half-hour mark could have put the game beyond doubt through Giovinco on two occasions. The former Juventus man twice failed to beat the goalkeeper from inside the box as Lazio were looking increasingly fragile.
Out of nowhere, however, the Biancocelesti managed to pull a goal back. In the 36th minute substitute Scaloni tried his luck with a powerful long-range strike from the right which deflected off a defender, sending Antonio Mirante the wrong way as the ball made its way inside the near post.
The tempo dropped rapidly after the break, although Lazio looked more committed in the final third. Reja's men, however, were struggling to create chances as time was running short.
Libor Kozak was guilty of a bad miss just after the hour mark as he headed over the bar following a superb delivery by Javier Garrido from a corner.
The Biancocelesti were made to rue their profligacy in the 72nd minute when Floccari struck home a cross by Giovinco to put the game beyond doubt. The 'Atomic Ant' himself nearly put the cherry on the cake shortly after but was denied by Marchetti after a superb solo run.
Following the win Parma are now 13th in the standings with 35 points, while Lazio are third with 51. The Gialloblu's next league game is a visit to Udinese on April 7, while the Biancocelesti host Napoli, their rivals for a Champions League spot, on the same day.