Mbh 8.79.1b

Thus addressed, Keshava quickly proceeded on his car, towards the mighty bowman Karna, for causing a single combat to take place between Karna and Savyasaci. Indeed, the mighty-armed Hari, at the command of Pandu's son, proceeded on his car, assuring (by that very act) all the Pandava troops. The rattle then of Arjuna's vehicle rose loud in that battle, resembling, O sire, the tremendous peal of Vasu's thunder. Beholding Arjuna of white steeds and having Krishna for his driver thus advance, and seeing the standard of that high-souled one, the king of the Madras, addressing Karna, said, "There cometh that car-warrior having white steeds yoked unto his vehicle and having Krishna for his driver, slaying his foes in battle. There cometh he about whom thou wert enquiring, holding his bow Gandiva. If thou canst slay him today, great good may then be done to us. He cometh, O Karna, desirous of an encounter with thee, slaying, as he cometh, our chief warriors. Do thou proceed against that hero of Bharata's race. Avoiding all our warriors, Dhananjaya advanceth with great speed, for, as I think, an encounter with thee, judging by his form swelling with rage and energy. Blazing with wrath, Partha will not stop from desire of battle with anybody else save thee, especially when Vrikodara is being so much afflicted (by thee). Learning that king Yudhishthira the just hath been exceedingly mangled and made carless by thee, and seeing (the plight of) Shikhandi, and Satyaki, and Dhrishtadyumna, the son of Prishata, and the (five) sons of Draupadi, and Yudhamanyu, and Uttamauja, and the brothers, Nakula and Sahadeva, that scorcher of foes, Partha, advanceth impetuously on a single car against thee. Without doubt, he is advancing with speed against us, avoiding other combatants. Do thou, O Karna, proceed against him, for there is no other bowman (among us that can do so). I do not behold any arrangements made for his protection, either on his flanks or at his rear.