Genoa seem to have Lazio's number, having done the league double over them the last two seasons. After soaking up constant pressure and relying on goalkeeper Mattia Perin to pull off a string of saves, the Grifone hit the Eagles with two second half sucker punches.
Juraj Kucka put the visitors ahead on the hour. Alberto Gilardino doubled the advantage from the penalty spot to leave a big question mark hanging over the future of Lazio boss Vladimir Petkovic. In comparison, Gian Piero Gasperini has taken ten points from a possible 15 since returning to the Genoa bench.
A win last weekend against Cagliari, followed by a midweek draw at AC Milan had relieved some of the pressure on Petkovic. The Bosnian had to shuffle his pack once again due to injuries and suspension. Senad Lulic, Andre Dias, Giuseppe Biava, Diego Novaretti, Abdoulay Konko and Lucas Biglia were all in the treatment room, while Lorik Cana and Stefano Mauri were banned. Hernanes wasn't even named on the bench after a poor first half display against Milan on Wednesday. Club officials said the Brazilian failed a late fitness test, but the rumours of a January exit will now pick up pace.
Federico Marchetti was celebrating his 100th game in goal for Lazio, while Francelino Matuzalem lined up against his former club. Gasperini was without late absentee Francesco Lodi after the midfielder failed a late fitness test. He joined Alessandro Gamberini, Emanuele Calaio, Mario Santana and Sime Vrsaljko on the Genoa sidelines.
Just five minutes in, Luca Antonini misjudged the bounce of the ball, allowing Felipe Anderson to get past him. The Brazilian pulled back looking for for Ogenyi Onazi, but Isaac Cofie made the crucial interception. At the other end, Michael Ciani stood tall to block Gilardino's shot.
Perin flew out to fist clear an Antonio Candreva cross to prevent Klose from getting on the end of it. Midway through the first half, the German rose highest to power a header at goal, but Perin made a superb point blank stop. A minute later, Klose stretched to meet a first time ball. This time, he beat Perin, but the ball trickled past the post and went wide.
Candreva appealed for a penalty on the half hour mark after Davide Biondini tugged his shirt. The referee wasn't interested and waved play on. Perin was by far the busiest of the two keepers. He punched clear a Bruno Pereirinha cross, then kept out a Candreva set piece.
Genoa awoke from their slumber just before the break. Giovanni Marchese crossed for Gilardino to head over and Cofie struck a shot from distance into Marchetti's gloves. Perin spilt a Candreva free kick right on half time, but the young custodian smothered the ball at the second attempt.
The visitors started the second half much like they finished the first. Gilardino chested down Biondini's pass to get a clear run on goal, forcing Marchetti to run out and smother.
Lazio had another penalty appeal turned down just two minutes after the restart. Anderson's cross was handled by Luca Antonelli after the defender left his arms extended. The referee turned down the home side's appeals once more. Perin continued to be a thorn in Lazio's side when he prevented Stefan Radu from turning in a corner and got to the follow up before Klose.
Just as Petkovic planned a double substitution, Genoa hit Lazio on the counter attack, scoring against the run of play. Ioannis Fetfatzidis played in Kucka, who got away from Luis Cavanda to slot past Marchetti at the far post.
The Biancocelesti poured forward looking for an equaliser. Radu headed over from a corner at the near post, then Ederson saw a shot blocked by Daniele Portanova. Gasperini shifted to a defensive formation and brought off Kucka, yet his side were given a gift with 20 minutes left to play. Lazio hit the self destruct button when Ciani flapped away Luca Antonelli's ball in the box with his hand. The Frenchman was booked and will miss next weekend's trip to Parma, further stretching Lazio's defensive resources.
Gilardino had missed a spot kick against Parma in midweek, but he made up for it here by sending Marchetti the wrong way.
There was no way back for Lazio. Fetfatzidis could have made it three in the closing stages, but his left-footed effort went wide. A chorus of whistles rung around the Stadio Olimpico at the final whistle, with Petkovic's fate to be determined.
Lazio: Marchetti; Cavanda, Ciani, Radu, Pereirinha; Onazi, Ledesma, (Keita 73) Gonzalez; (Perea 61) Candreva, Klose, Felipe Anderson (Ederson 61)
Genoa: Perin; Antonini, Portanova, Manfredini; Biondini, Kucka, (De Maio 69) Matuzalem, Cofie, Marchese; (Fetfatzidis 46) Antonelli; Gilardino (Konate 77)
Goals: Kucka 60 (G) Gilardino pen 72 (G)