Arjun Hingorani's Dharmendra starrer - Kahani Kismat Ki -- and the Amitabh starrer -- Deewar (Salim Javed's) -- have an identical fight sequence -- the hero locks up the door, passes the key to the main villain and declares that he himself will pull out the key from the villain's pocket to open the door

After this there's a fight in which of course the hero keeps his promise...

The climax of J.P. Dutta's BATWARA (Vinod Khanna and Dharmendra on horseback, separate horses, catch hold of villain Amrish Puri, one arm each, and smash him against a rock while riding out together), is the same as that of Mukul Anand's KHUDA GAWAH (Sridevi and Amitabh on separate horses catch hold of Kiran Kumar, taking one arm each, and smash him against a rock).