"So Haman got the robe and the horse. He robed Mordecai and led him on horseback through the city streets, proclaiming before him, 'This is what is done for the man the king delights to honor!'" NIV translation
The proud man is reduced to leading the horse of the man he hates the most through the streets of the city.
"Afterward Mordecai returned to the king's gate. But Haman rushed home, with his head covered in grief, and told Zeresh his wife and all his friends everything that had happened to him. His advisers and his wife Zeresh said to him, 'Since Mordecai, before whom your downfall has started, is of Jewish origin - you cannot stand against him - you will surely come to ruin!'" NIV translation
Haman went home upset about this turn of events. He called his wife and friends together and told them what had happened. This is the same group of people that had told him to have the gallows built to hang Mordecai. Now, they tell him that, because Mordecai is a Jew, he is doomed and cannot stand against him.
It is awesome to see what God can and will do as he has used these events to get Haman's friends and family to see that He takes care of His own people.
"While they were still talking with him, the king's eunuchs arrived and hurried Haman away to the banquet Esther had prepared." NIV translation
Even though he didn't feel like going, he still had to go to the banquet. God has taken care of His own people and now He is going to deal with the man that opposes His people. If you are a child of God, then you do not have to worry about dealing with your enemies because God will handle it just as He did here with Mordecai.