YMMV but you could book it under your name and then call the hotel later to tell them you'd be sharing the room and will be arriving late and could they please add the other guest's name to the room so they can check in when they arrive first.
I did this (legitimately) with a free weekend night from this promo (St Regis San Fran). My buddy really did show up hours before me and they let him check in, but like i said, YMMV, and I really did come in later. Note, in this case I had 2 rooms, one for me and one for him (both free weekend nights), so that could have had something to do with it.