An interesting display here, Mariusz showed once again that his striking is fast-paced, explosive, aggressive, and completely undisciplined. Despite his lack of technique, he spends so much time striking that his opponent can't even get a punch in edgewise. However, this isn't exactly new, he showed this in his first fight.
One thing we saw from him that we haven't seen before was wrestling. He said he'd been training his wrestling nonstop and it shows. He scored several takedowns, both clinch and shoot, and displayed an ability to move fairly easily to half guard from full. Unfortunately, we saw very little else from him on the ground, there were no attempts at submissions and very little ground and pound. He was stood up multiple times for inactivity. He also didn't seem to understand how to pass the guard, either that or he simply didn't want to because he skipped several easy opportunities.
His opponent spent most of the fight holding on for dear life, on the feet he was getting battered or clinched against the ropes, and on the ground he was on his back the whole time. I think the only damage he did to Mariusz was a couple of leg kicks.
That said, the fact that Mariusz was unable to finish, or indeed inflict any more visible damage on Kawaguchi than a bloody nose, indicates that a smaller, weaker fighter with more experience can still pose a challenge to Mariusz simply because he is so new to the sport. At this point, Brock would smash him. On the other hand, the fact that they went ten minutes and Mariusz looked strong and aggressive at the end demonstrates that he does indeed have a deep gas tank, despite some people's doubts.
At this point in his career Sylvia is a good choice for Mariusz. Tim is a difficult guy to grapple with- he may not be much of a submission threat, but has been able to survive with some of the best HW grapplers out there. And if anyone's striking will give Mariusz fits it will be Sylvia's plodding rangy attacks. I look forward to this next test.