Mega Drive is probably earliest that was capable of it really, but Namco System 21 and especially Sega Model 1 (1990) were designed with 3d/polygons in mind but

Mega Drive is probably earliest that was capable of it really, but Namco System 21 and especially Sega Model 1 (1990) were designed with 3d/polygons in mind but have relatively old chips in them. Programming for those things could not have been easy.