Marathas of Scindia had evacuated the Jaipur territory, after the failure of Lalsot campaign of July 1787. In early 1790, the situation was expected to completely rid the Rajputana off Maratha interference, Rajput nobility managed to move away the Mughal general Ismail Beg over to their side. It was tried too hard to prevent the junction of Ismail Beg with his Rajput allies, Madhavrao Scindia, who dispatched an army under his generals Benoît de Boigne and Gopal Rao Bhau. Marathas came upon Ismail Beg at Patan on the morning of 10th May.
For over three weeks, nothing changed between the two armies. On 19th June, Ismail Beg expressed his purposes of attacking the Maratha lines. By this time, his Rajput associates had come to his aid. General de Boigne went ahead to advance and confront the Mughals with all his force the next morning. De Boigne's restricted brigade and artillery guns created the leader of Maratha attack and occupied the central position in the Maratha lines. The Maratha captains Ambaji Ingle and Balaji Ingle ordered the left wing, opposite Ismail Beg, while the Holkars commanded the right wing. Gopal Bhau supervised the Deccan cavalry, which formed the core. The armies of the either teams faced each other in east-west direction along a straight line.
Ismail Beg's party formed the southern wing of Rajput-Mughal combine and the Rathore horsemen and Abdul Mtalab's (Ismail Beg's lieutenant) battalions followed the former group. A majority of the Rajput cavalry was concentrated in the central wing. The left wing was formed entirely by Jaipur Nagas, while fighting the monks. The union had over 125 artillery pieces at its removal. They were placed in three rows, one before Ismail Beg and the other before Matlab and the remaining one, the channels of Jaipur Nagas.
Maratha artillery under de Boigne's brigade was smaller in number, but was much more rapid, accurate and mobile than the others ones in possession of their adversaries. Battle of Patan started in the form of irregular clashes and evolved into an all out battle only at its end. The command of Rajput-Mughal army was never really united and had no solid plan of action. It was this lack of organization that was instrumental in a decisive Maratha victory as the Marathas had the scheme and the element of surprise was made on their side. At the beginning of the battle, neither side was in haste to come into control.
The Maratha army went forward with arms after noon and advanced four miles westwards from their camps to the mouth of the pass leading to Patan. But it took their opponents over a quarter of a day to take up proper positions on the hill overlooking the pass. However hostilities didn't break out for six more hours. It was ekadashi, considered as an auspicious day in the Hindu calendar. Hindu soldiers on both sides were observing a religious fast and exchange of fire during this period occurred only between the Muslim soldiers on both sides. At dusk, Rajputs and their Muslim partners went back to their respective camps. The Maratha army however held its positions at the mouth of the pass. The actual battle however suddenly started in the evening by an unpredicted skirmish. Some Maratha Pindaris from the left wing of Maratha lines, managed to get hold of animals that were a part of Ismail Beg's group. This unavoidably led to a small conflict with Ismail Beg's men. General de Boigne then directed his guns on Ismail Beg's troops. They were suddenly caught and the murderous fire of Maratha guns proved to be deadly. Gopal Bhau and de Boigne were killed and the Marathas descended upon enemy camps. Taken aback by the suddenness and the fierceness of the Maratha attack, Rajput resistance yielded and the Jaipur Nagas held on to their positions before finally being overwhelmed at around 9 pm in the night.
Rajput horsemen managed to run away into the countryside, but the skilled Mughal and Rajput battalions took shelter in the Patan city. All the arms and property of Rajput-Mughal association left in the field was captured. On 22st June, de Boigne went with some guns to the gates of Patan city and endangered its ruler, Raja Sampat Singh with attack. The Raja was powerless to resist. Some battalion commanders managed to flee, but most battalion commandants along with 2000 cavalry and 10,000 sepoys surrendered. General de Boigne then proceeded to lay a siege to the fort o Patan. The defenders of the fort gave up within 6 hours and the victors conquered all the riches of Patan. The Marathas could recover over 105 pieces of artillery from the enemy, along with 1300 camels, 21 elephants and 300 horses. Rajputs could not get back more than 5 battalions and 3000 Rathore horsemen.
Ismail Beg's army was practically wiped out; it ceased to exist as a military unit and lost all its arms, equipments, tents, baggage and even cooking pots. Marathas on their part lost more than 52 cavaliers and 300 sepoys. European armed and trained Marathas; Rajput states were devastated against one another. Marathas managed to triumph over Ajmer and Malwa from Rajputs. Although Jaipur could not win the battle, it remained unbeatable. Battle of Patan, effectively ended Rajput hopes for independence from peripheral interference. From the day of Patan (20th June 1790) to the 2nd of April 1818, Jaipur entered into protecting additional coalition with the British government and lay the darkest period in the history of Jaipur kingdom.
This victory increased Scindia's influence over the Peshwas (Maratha Prime Ministers) in Pune, the seat of Maratha government. The Battle of Patan along with the subsequent gains helped Marathas regain lost influence and morale, which had been badly shaken by the Panipat disaster. The Maratha association however could not unite on the gains and soon fell to internal strife. The Marathas ultimately lost their control to the British in 1817.