Territorial Tussle?

I was about to start getting ready to head out for an appointment, when two hawks swooped past the window, landing in a heap at the edge of the yard. I was horrified, because one (on the left in the photo) seemed intent on putting an end to the other. After holding down the one on the right for at least five minutes, the right rose up and started to show the left that it wasn't going to be that easy.  After at least ten minutes more, the right ended up in control, as you can see in the extra.

I've seen aerial spats between raptors in the air many times, but never on           the ground. I didn't want to leave before things were settled, but I was already late. Unfortunately, these were taken through the window so the quality is less than ideal.  When I returned home, they were long gone.  I checked the spot and the only evidence left behind was a few fluffy feathers.

I'm assuming this was a territorial spat, although I would love to have both hawks return.  I could use some help with the ID.  I'm thinking they are both immature Red-shouldered, but I certainly could be wrong.