Why did Karna enter with Vijay’s bow on the 17th day?

Why did Karna enter with Vijay’s bow on the 17th day? Karna had the last opportunity to defeat Arjuna. He was the only powerful warrior who was left in Kaurava side Karna used divine bow finally because he can't retreat from the encounter if someone destroys his normal bow . Divine bows like Gandiva and Vijaya are indestructible in nature.