In the Third battle of Panipat, during the Maratha Conquests, he allied himself with the Durranis led by Ahmad Shah Durrani (also known as Ahmad Shah Abdali, against the Marathas. Najib Khan was clever enough to understand changed ground realities after third battle of Panipat. His brilliant political acumen was used by Ahmed Shah Abdali to isolate Marathas &amp; preventing them from getting even single ally during their conflict with Durrani's power. His opposition to signing of treaty, with Marathas was the main cause of battle being fought at Panipat. He not only provided, Ahmed Shah Abdali, with 40,000 Rohilla troops but also 70 guns to the combined forces. He also convinced Shuja-ud-Daula, the Nawab of Oudh, to join Ahmad Shah Abdali's forces against the Marathas. In this battle, the Maratha's were defeated and as a consequence Rohilla Pakhtuns increased in power. However, the Marathas recovered in a short duration of 10 years and under Mahadji Schinde recaptured Delhi in 1771, reinstalling the weakened Mughal emperor Shah Alam II to the throne, under Maratha suzerainty.