If I'm remembering correctly, old Zab Judah of all people may have made him looking the most uncomfortable late in their fight. He was landing some seriously sharp and hard straight lefts on Danny's mug in that one.
I think Judah at the end of their fight hit him with two flush bombs that buzzed him more then any other time but he didn't buckle
Yep his chin is iron. I also can't help to notice the size of his cranium. Most fighter with big head size can take a punch better, some also appears bigger than his opponent may be because it's correlate with having stronger bone structure. I'm sure there are exceptions. Some recent fights comes to mind: Charlo-Williams, Crawford-Molina and Hurd-Harrison.