Empoli stunned Lazio by scoring two late goals to snatch a 2-2 draw in the Italian capital on Sunday.
Lazio appeared to have the match won when Mattia Zaccagni doubled its lead early in the second half, following a header by Felipe Anderson with less than two minutes on the clock.
However, Francesco Caputo pulled one back for the visitors seven minutes from time and Răzvan Marin netted a surprise equaliser in stoppage time.
Lazio was three points behind fourth-placed Inter Milan, which was held to a 2-2 draw at Monza on Saturday.
Roma can leapfrog Lazio later with a win at AC Milan, which will be looking to move back into second spot. League leader Napoli was also playing later, at lowly Sampdoria.
There were clashes between Roma fans travelling to Milan and Napoli supporters heading to Genoa. Around 300 fans were involved, throwing flares, stones and other objects at each other, causing part of the motorway to be closed and lengthy queues to form.
Spezia inched four points clear of the relegation zone with a 0-0 draw at home to Lecce, while Salernitana drew 1-1 against Torino.