Arjuna, disguised as a Brahmana, defeats Karna in battle
Enraged that a Brahmana has won the contest, the kings led by Karna attack, declaring it permissible to kill a Brahmana who fights. Arjuna, still in disguise, takes up his bow and meets Karna's charge. Their duel is so fierce and skilled that Karna, stunned, begins to wonder if he is fighting a god in disguise.
The kings were furious. A Brahmana had drawn the bow and won the princess. Led by Karna, they prepared to attack the Brahmanas in the arena. Some of the Brahmanas shook their deerskins and water pots, ready to fight. Arjuna smiled and told them to stand aside as spectators. "I will repulse those kings," he said, "like poisonous snakes."
He took up the bow he had just won — the bow of the swayamvara — and stood with his brother Bhima like an immovable mountain. Seeing the Kshatriyas advance, Karna at their head, the two brothers fell upon them like two elephants charging a herd.
The kings rationalized their assault. "It is permissible," they said, "to kill a Brahmana who is willing to fight."
Then Karna rushed at Arjuna, eager for battle like an elephant over a female. Shalya rushed at Bhima. Duryodhana and the others rushed at the Brahmanas, who fought back lightly, almost carelessly.
Arjuna saw Karna coming. He stretched his mighty bow and pierced him with three arrows. The impact stunned Karna, and he approached again with greater caution. What followed was a violent duel between two invincible warriors, each determined to vanquish the other. They fought with such speed they became invisible to the onlookers. They taunted each other in the coded language of warriors — "Look at the strength in my arms," "See how I countered that."
Karna saw the valour in Arjuna's arms, unparalleled on earth, and fought even more vigorously. He repulsed Arjuna's swift arrows and shouted aloud, drawing applause from the warriors.
Then Karna spoke, his tone shifting from rage to something like awe. "O foremost among Brahmanas! I am pleased with the strength of your arms, which do not tire, and with your supreme control over weapons. Are you Rama, the personification of the knowledge of weapons? Or are you Harihaya himself? Or Achyuta Vishnu? Have you assumed this form to disguise yourself? When I am angry in battle, no one except Shachi's husband and Pandava Kiriti can withstand me."
Arjuna replied, "O Karna! I am not the science of weapons personified. Nor am I the powerful Rama. I am only a Brahmana, a chief among warriors. Through my preceptor's grace, I am skilled in the use of brahma and paurandara weapons. Wait for a bit. I stand here today to vanquish you."
At these words, Karna withdrew from the battle. The maharatha had reached a conclusion: Brahmana strength was invincible.