Thinking over the Zab-Tyzsu fight, i think Tyszu was just measuring Zab in the first round by showing him respect.....Zab started quickly and tagged Tyzsu a few times.
In the second round Zab may of been more hesitant because he wasn't the same whirlwind he was in the first, Tyszu was not going to be knocked out with 1 punch and certainly wasn't going anywhere.
I think Tyzsu might of imposed his will and his punching power in the mid-stages of the second round, and was certainly closing the distance..
Judah was caught flush with his hands down and got knocked out, very short fight indeed.