In the Battle of Dharmatpur, Jaswant Singh opposed Aurangzeb. The battle was fought on 15th April 1658, fifteen miles from Ujjain. Jaswant could have attacked Aurangzeb but he allowed Murad's armies to join Aurangzeb. He was desirous of beating both Mughal princes at once. This delay allowed Aurangzeb to win over the Mughal general, Kasim Khan, who was sent by Shah Jahan to help Jaswant Singh. Kasim Khan defected as soon as the war started but 30,000 rajputs of Jaswant decided that they would not leave the field. Some prominent generals in Maharaja's army were Mukund Singh Hara of Kotah and Bundi, Dayal Das Jhala, Arjun Gaur of Rajgarh in Ajmer province and Ratan Singh Rathore of Ratlam. Jaswant attacked both Aurangzeb and Murad and they barely escaped. According to James Tod in Annals and Antiquities of Rajasthan:
Ten thousand Muslims fell in the onset, which cost seventeen hundred Rathores, besides Guhilotes, Haras, Gaurs, and some of every clan of Rajwarra. Aurangzeb and Murad only escaped because their days were not yet numbered. Notwithstanding the immense superiority of the imperial princes, aided by numerous artillery served by Frenchmen, night alone put a stop to the contest of science, numbers, and artillery, against Rajput courage.
Finally the unequal contest ended and Aurangzeb named the place of victory Fatehabad. In this battle Durga Das Rathore changed four horses and lost about half a dozen swords (they broke due to intense fighting) and he finally fell down half dead. Maharajah ordered him to be carried away. After his wounds healed he promptly rejoined Maharaja's army. James Tod further writes in Annals and Antiquities of Rajasthan:
Rajputs, even in the moment of battle, worshipped the rising sun, and they sealed there faith in there blood; and none more liberally than the brave Haras of Kotah and Bundi. . . The annals of no nation on earth can furnish such an example, as an entire family, six royal brothers of Kotah, stretched on the field, and all but one in death. Of all the deeds of heroism performed on this day, those of Ratan Singh Rathore of Ratlam, by universal consent, are pre-eminent, and are wreathed into immortal rhyme by the bard in the Raso Rao Ratan.
Sighs never ceased flowing from Aurang's heart while Jaswant lived. . . had all the princely contemporaries of Jaswant- Jai Singh of Amber, Rana Raj Singh of Mewar, and Chattrapati Shivaji coalesced against their national foe, the Mughal power would have been made extinct. Could Jaswant, however, have been satisfied with the mental wounds he inflicted upon Aurangzeb, he would have had ample revenge; for the image of the Rathore crossed all his visions of aggrandizement. The cruel sacrifice of his heir, and the still more barbarous and unrelenting ferocity with which he pursued Jaswant's innocent family, are the surest proofs of the dread which the Rathore prince inspired while alive.
Aurangzeb tried to kill Jaswant Singh many times. James Tod writes in his Annals and Antiquities:
It was by the vigilance of this chief (Mokund Das Kumpawat), and his daring intrepidity, that the many plots laid for Jaswant's life were defeated. He had personally incurred the displeasure of Aurangzeb, by a reply which was deemed disrespectful to a message sent by the royal "Ahadi" (royal messenger), for which the tyrant condemned him to enter a tiger's den, and contend for his life unarmed. Without a sign of fear he entered the arena, where the savage beast was pacing, and thus contemptuously accosted him: "Oh, tiger of the Miyan, face the tiger of Jaswant"; exhibiting to the king of the forest a pair of eyes, which anger and opium had rendered little less inflamed than his own. The animal, startled by so unaccustomed salutation, for a moment looked at his visitor, put down his head, turned around and stalked from him. "You see" exclaimed the Rathore, "that he dare not face me, and it is contrary to the creed of a true rajput to attack an enemy who dares not confront him".