At the given signal Bandini and Pazzi were to stab Giuliano and the two priests were to stab Lorenzo.

The signal was the breaking of the Eucharistic wafer, and at this solemn moment Giuliano was instantly killed, with one stab in the heart and nineteen elsewhere, Francesco so overdoing his attack that he severely wounded himself too; but Lorenzo was in time to see the beginning of the assault, and, making a movement to escape, he prevented the priest from doing aught but inflict a gash in his neck, and, springing away, dashed behind the altar to the old sacristy, where certain of his friends who followed him banged the heavy bronze doors on the pursuing foe.

Those in the cathedral, mean-while, were in a state of hysterical alarm; the youthful cardinal was hurried into the new sacristy; Guglielmo de' Pazzi bellowed forth his innocence in loud tones; and his murderous brother and Bandini got off.
Order being restored, Lorenzo was led by a strong bodyguard to the Palazzo Medici, where he appeared at a window to convince the momentarily increasing crowd that he was still living.

Meanwhile things were going not much more satisfactorily for the Pazzi at the Palazzo Vecchio, where, according to the plan, the gonfalonier, Cesare Petrucci, was to be either killed or secured.

The Archbishop Salviati, who was to effect this, managed his interview so clumsily that Petrucci suspected something, those being suspicious times, and, instead of submitting to capture, himself turned the key on his visitors.