Both fighters were engaged in a fairly entertaining scrap prior to the ending of the fight, with both getting in some big striking exchanges and doing damage to the other. It was a far cry from their much derided third bout in the UFC, and it was much easier to watch.
Finally, as the second round was wearing down, Arlovski dropped Sylvia with a massive overhand right to the jaw, then went in for the kill by landing two soccer kicks to Sylvia's shoulder and head area. Now, ONE FC's rules do allow soccer kicks, but there's a catch: the referee must signal to a fighter that they are allowed an "open attack" when they've knocked their opponent down. Referee Yuji Shimada didn't call for the "open attack," and thus deemed Arlovski's soccer kicks an illegal foul.
Sylvia, who had just been knocked down in what should have been a TKO finish for Arlovski, was then allowed five minutes to recover while Shimada and ONE FC officials conferred in the cage. Ultimately, Sylvia (smartly) decided he couldn't continue, and the fight was deemed a "no contest."
Arlovski and Sylvia then exchanged a few words in a seemingly friendly conversation, then told interviewer/commentator Jason Chambers that they'd be up for a fifth fight to settle this one.
Penick's Analysis: The "open attack" rule is a ridiculously unnecessary and detrimental rule for a fight, and ONE FC obviously didn't do a very good job in explaining it to Arlovski beforehand. Having to delay your instincts to wait for a referee signal only allows the fighter who got knocked down to recover. In this situation, Arlovski thought the soccer kicks were legal, and that's what he went for. You either allow them or you don't, but adding an extra step screwed Arlovski over here, as Shimada failing to call for the ridiculous "open attack" cost him a victory. And that's the other thing here, as well, because had soccer kicks simply been illegal, Arlovski would have pounced with punches and the win would still be his.