They struck twice in the first five minutes of the game, Josip Ilicic beating goalkeeper Lukasz Skorupski from outside the penalty area and scoring again just 122 seconds later.
Ilicic then turned provider as the hosts made it 3-0 in the ninth minute, setting up Hans Hateboer for a right-footed finish that continued Atalanta's dominance.
Incredibly they were still not finished as Bologna continued to slump, with Remo Freuler teeing up Duvan Zapata for his 20th Serie A goal of the season.
No Serie A team had scored four goals so early in a match since Juventus made a similarly rapid start in a game against Roma all the way back in March 1932.
Bologna did at least get on the scoresheet in the second half, with Riccardo Orsolini picking out the top-right corner with a long-range strike.