Slightly better quality:

 

https://www.youtube.com/watch?v=fI2Bh786bos

 

I thought this was boring when I watched it a few years, but now that I've seen more from this time period I'd call it some pretty solid grappling, though still not really that special. Match picks up for the finish, though, with Sonnenberg pulling out these insane running headbutts and Nagurski weathering the storm and looking for an opportunity to capitalize on a mistake.

This match is for the Undisputed World Heavyweight Championship, original lineage