The brawl begins when Tybalt insults Romeo and his family. Romeo tries to avoid the fight, but Tybalt is determined to start something. He draws his sword and challenges Romeo to a duel. Romeo is reluctant to fight, but he knows that he cannot back down. He draws his own sword and the two men begin to fight.
The fight is fierce and bloody. Tybalt is the more skilled swordsman, but Romeo is determined to win. The two men trade blows for several minutes, and the crowd of onlookers cheers them on.
Finally, Romeo gains the upper hand. He manages to land a fatal blow on Tybalt, and Tybalt falls to the ground dead. Romeo is horrified by what he has done, but he knows that he had no choice. He has killed Tybalt in self-defense, but he knows that the Capulets will never forgive him.
The brawl is a turning point in the play. It sets in motion a chain of events that will eventually lead to the deaths of Romeo and Juliet.