First off how the speech was so persuasive was how he started off; "I come to bury Caesar, not to praise him." Antony, contrary to what he says, actually means to turn the citizens of Rome against Brutus and the conspirators, revenging Julius Caesar's death. Antony continues his speech by using the idea from Brutus' speech that Caesar was an ambitious man. Brutus used this thought to support his basis for killing Julius Caesar.
Next he goes on to say that, "For Brutus is an honorable man." However, Antony does begin to disagree with Brutus' comment on Caesar's grievous ambition. He does this be appealing to the audience's logic, and presents two strong examples of Caesar's lack of ambition. "He hath brought many captives home to Rome, Whose ransoms did the general coffers fill; did this in Caesar seem ambitious?" So he goes on about Caesar and him not being ambitious.
Finally he continues to say that Brutus is an honorable man. But he continually repeats this line, even after he has just disproved Caesar's ambition, making the compliment sound sarcastic and mocking. By proving to the audience that Caesar was not full of ambition, he also proves that the conspirators were not honorable men, thus concluding that Caesar's death was a futile murder, devastating to the welfare of Rome. Antony also uses parison, repeating the same idea continually, only rephrasing it slightly each time.
So Mark Antony's speech against Brutus persuaded the Roman people. Antony's speech successfully incorporates a host of persuasive language devices, most important of them being sarcasm and irony. The great skill of rhetoric and oration Anthony displays...