Lazio won at relegation-threatened Frosinone by an unconvincing 1-0 in Serie A to remain firmly in the race for a Champions League place on Monday.
Felipe Caicedo scored to send Lazio level on points with capital city rival Roma, one point behind fourth-place AC Milan.
But Atalanta leapfrogged Lazio into fifth place just two hours later with a 1-0 win of their own against Cagliari, who remain just four points above the relegation zone.
Hans Hateboer scored early in the second half and Atalanta held on to their slender lead to go level on 35 points, but ahead on goal difference, with Roma and Lazio.
The top four teams in Serie A qualify for the Champions League.