Ian Scheckter (Jody Scheckter's elder brother) was signed for Arrows in 1978, Arrows then broke the contract and put Patrese in the car, a court injunction was taken out and a settlement was negotiated that left Patrese with the drive.
Patrese lead the 1978 South African GP before the car blew its engine.
https://www.youtube.com/watch?v=zGSOtL5k_SY