We accomplished truly scalable, low cost, arbitrarily large-area block copolymer lithography, synergistically integrating the two principles of graphoepitaxy and epitaxial self-assembly. Graphoepitaxy morphology composed of highly aligned lamellar block copolymer film that self-assembled within a disposable photoresist trench pattern was prepared by conventional I-line lithography and utilized as a chemical nanopatterning mask for the underlying substrate. After the block copolymer film and disposable photoresist layer were removed, the same lamellar block copolymer film was epitaxially assembled on the exposed chemically patterned substrate. Highly oriented lamellar morphology was attained without any trace of structure directing the photoresist pattern over an arbitrarily large area.