The hype was heavy for the Japanese fighting sensation, as he came into the bout ranked number three in the world at 145-pounds. But could he pay it off against the always game Roop?
Unfortunately, no, he could not. But he did earn himself a split decision victory, much to the chagrin of the crowd inside the Mandalay Bay Events Center.
This one will be hotly contested for some time to come. Hioki clamed in the post-fight interview that Japanese MMA is not dead. After this bout, he might find more than a few arguments to the contrary.
The opening round started -- as they all do -- with both men standing, trying to find their range and timing. The air got more of a workout than either combatant, as neither was able to land with any meaningful shots.
Hioki's vaunted ground game was on display for a short time, a brief flash of potential, but the round came to a close with no one man getting the clear advantage.
Roop opened up his arsenal in the second frame, easing into a comfort zone with his kicks. But it cost him halfway through as Hioki earned a takedown into full mount that he used to threaten with submissions.
That smothering, elite mat work we heard so much of had made its way inside the Octagon.
Still, Roop survived to the final round, even throwing a few taunts before heading to his corner for some last minute advice.
His cornermen told him to take Hioki down and that's exactly what he did, wasting no time executing a nice slam. He did nothing with it, but it looked pretty.
And scored points.
Roop used the rest of the round to control his foe, taking him down once more and simply riding out the round.
But when the scorecards came in, they read in favor of Hioki, who took home the split decision.
You okay with this one, Maniacs?