This was not a one sided fight at all. It was very back and forth.
Round 1 Jiri gets - literally - kicked to the ground in 50 seconds. By the middle of the round his leg is swollen and bruised and he's not sure footed. He resorts to wrestling (smart) but gets exactly zero done on the ground. He can't work a submission, he can't progress position, he's not landing any shots. Alex gets up and escapes, the round ends.
I would say Round 1 Jiri was in serious danger and wisely resorted to grappling, but we get a view of both of these guys fresh on the mat and Jiri can't even hold him down, let alone win the fight there.
Round 2 some more pretty nasty leg kicks, Jiri is switching stances. He starts getting a little wild and lands a few shots, but he's not able to even stun Alex, let alone hurt him in a meaningful way. He has to put himself in danger to get in those exchanges, and sure enough the third time he goes for a his wild guy flurry, he gets dropped like a sack of potatoes.
This wasn't a particularly competitive fight and I very much enjoy watching Jiri. He's about as entertaining as MMA fights get, but he can't do his typical style of 'take your punch to land my own' against a hitter like Poatan. That fights ends in Jiri getting knocked out every time.
Now? With zero training camp, coming off a broken toe, straight up off the couch? Jiri should win this. Wrestling a striker who has zero cardio preparation for a 5 round fight is a whole different animal. Alex is nuts for taking this fight.