Back-up strikers Julio Cruz and David Suazo tore Atalanta apart as champions Inter Milan stretched their lead at the top of the Serie A table to three points with a narrow 2-1 victory on Saturday.
Roma kept up their title push after Christian Panucci headed a last-minute winner to give them a 1-0 away win at Genoa which left them second, for a day at least.
Atalanta's away fans had been barred from the San Siro stadium due to the recent crowd violence in Italy, with instead 5,000 children invited to sit in the stand usually reserved for visiting fans.
And they were treated to a first-half masterclass between Latin Americans Cruz and Suazo, playing in place of the rested Zlatan Ibrahimovic and Hernan Crespo.
Argentine Cruz played in his Honduran strike partner on 10 minutes to open the scoring with a fierce near post strike.
And on the half hour mark, Cruz mopped up the spoils from close range after Suazo's looping shot beat Atalanta goalkeeper Ferdinando Coppola but came back off the post.
Atalanta were far from out of it though. Inter's goalkeeper Julio Cesar brilliantly denied Antonio Langella from close in. Then Sergio Flocarri scored after taking the ball on his chest on the edge of the penalty box, swiveling and hitting a dipping volley into the top corner, giving Cesar no chance.
Inter were far from convincing after the break and had to suffer several nervy moments before hanging on for the victory that extended their unbeaten start to the season to 12 matches.
In Genoa, Panucci was the unlikely match-winner for the second time in a week, having scored late in Italy's 2-1 victory against Scotland -- the result that sent the world champions to the Euro 2008 finals.
Roma were missing four first-team regulars, including captain Francesco Totti, but they made light of those absences.
Genoa almost took the lead in the second half when Matteo Paro shuddered the upright with a rasping, curling effort from outside the box that had Roma's Brazilian goalkeeper Doni well beaten.
Roma could have taken the lead themselves 15 minutes from time but Genoa goalkeeper Rubinho made a stunning double save to keep the hosts on level terms.
He tipped Mirko Vucinic's firm header onto the bar before diverting De Rossi's close range follow-up with his outstretched leg.