Miroslav Klose struck a superb late winner for Lazio as the Biancocelesti beat Inter Milan 1-0 at the Olympic Stadium on Saturday to indirectly boost Juventus's hopes of extending their lead before Christmas.
Inter started their 17th match of the campaign only four points behind champions Juve at the top of Serie A, however Andrea Stramaccioni's men were dominated throughout before missing several chances late on.
Stramaccioni's anger showed as he walked off the pitch following a fifth defeat of the campaign which means Juventus can now extend their lead over the Nerazzurri to seven points if they beat Atalanta in Turin on Sunday.
Lazio had beaten Inter only twice in their last 15 league games although one of those wins was last time out at the Olympic Stadium in March.
And with Lazio unbeaten at home since a shock 1-0 reverse to Genoa at the end of October -- combined with Inter's poor away form of late -- Vladimir Petkovic had every reason to believe the Biancocelesti could produce a result.
Inter threatened first, Federico Marchetti diving quickly to smother the ball as Diego Milito pounced on a chest-down following Yuto Nagatomo's looping cross from the right.
But the visitors created few chances in an opening half in which Cristian Ledesma saw a powerful shot from distance go just wide, while Stefano Mauri just failed to muster a shot from inside the area.
Lazio's claims for a penalty fell on deaf ears after Klose tumbled to the ground as he and Inter defender Alvaro Pereira crossed paths on the edge of the area when Senad Lulic hit an inviting cross in.
Stramaccioni tinkered with his formation at the interval, but although Inter came fighting back late on Lazio, despite a dubious start, remained in control.
The hosts wasted two freekick chances within minutes after Klose had come in for harsh treatment from the Inter defence, with Walter Samuel shown yellow for the second offence.
Lazio's frustrations grew when, at the end of a well-worked move, Brazilian Hernanes sent a first-time shot high and wide from 20 metres.
The hosts, however, were lucky to escape when Fredy Guarin was allowed to power up the middle to unleash a shot which had Marchetti at full stretch, while moments later Milito's weak effort trickled wide of the keeper's post.
Inter finally had some momentum but Nagatomo failed to tap home after Antonio Cassano's well-placed shot from the Japanese defender's lay-off had come off the post after a superb parry by Marchetti.
Not to be outdone, Lazio spurned two chances of their own moments later.
First Antonio Candreva saw his angled shot parried by Handanovic, then Klose was let down by poor control when he collected Alvaro Gonzalez's inch-perfect cross from the right while in alone on goal.
When Klose came down in the area after a tackle by Samuel, Lazio saw their claims for a penalty waved away for a second time.
Klose's persistence, however, was to pay off, the German finally beating Samir Handanovic with a well-placed strike from the edge of the area after running on to Mauri's incisive through ball.
Inter rallied and in the dying moments caused panic in the Lazio area but the hosts held on for a win which left them in fourth but level on points with third-placed Napoli.