Atalanta's game was pretty good. We cannot always see them scoring 5 goals, they are not actually a top scoring team, but they showed a good performance.
I don't think they will rise to the top of the league rankings. Fiorentina has been losing points for 2 weeks and will not lose any more points in the next match. The match that will be really exciting will be the next match. They will play against Lazio, both teams have the same goal and their strengths are very close to each other

Atalanta's opportunity to overtake Fiorentina is still wide open. Fiorentina's next match will face Inter. Even though you are playing at home, it is clear that facing Inter, who is currently at the top of the standings, will not be easy. while Atalanta will face Udinese, which could be a good opportunity to unseat Fiorentina if they fail to win against Inter.
The difference in points with the top 3 teams is quite large. Now the fight for 4th place in the standings will probably only happen to Fiorentina, Atalanta, and Lazio.