Mbh 9.58.2c

They then resembled, O monarch, two oceans agitated by the tempest. Striking each other equally like two infuriated elephants, their clashing maces produced peals of thunder. During the progress of that dreadful and fierce battle at close quarters, both those chastisers of foes, while battling, became fatigued. Having rested for a while, those two scorchers of foes, filled with rage and uplifting their maces, once more began to battle with each other. When by the repeated descents of their maces, O monarch, they mangled each other, the battle they fought became exceedingly dreadful and perfectly unrestrained. Rushing at each other in that encounter, those two heroes, possessed of eyes like those of bulls and endued with great activity, struck each other fiercely like two buffaloes in the mire. All their limbs mangled and bruised, and covered with blood from head to foot, they looked like a couple of Kinsukas on the breast of Himavat. During the progress of the encounter, when Vrikodara (as a ruse) seemed to give Duryodhana an opportunity, the latter, smiling a little, advanced forward. Well-skilled in battle, the mighty Vrikodara, beholding his adversary come up, suddenly hurled his mace at him. Seeing the mace hurled at him, thy son, O monarch, moved away from that spot at which the weapon fell down baffled on the earth. Having warded off that blow, thy son, that foremost one of Kuru's race, quickly struck Bhimasena with his weapon. In consequence of the large quantity of blood drawn by that blow, as also owing to the violence itself of the blow, Bhimasena of immeasurable energy seemed to be stupefied. Duryodhana, however, knew not that the son of Pandu was so afflicted at that moment. Though deeply afflicted, Bhima sustained himself, summoning all his patience. Duryodhana, therefore, regarded him to be unmoved and ready to return the blow. It was for this that thy son did not then strike him again.