Yan's first defense is Merab III at UFC 333.

Petr Yan (20-5) is the UFC bantamweight champion again. He took a unanimous decision over Merab Dvalishvili at UFC 323, ended Merab's reign, and reset 135 overnight. Zero defenses on the ledger. First defense already booked: Yan versus Merab III at UFC 333 on Oct. 24 in Abu Dhabi. Trilogies do not get cleaner scheduling than that — the champion's first night back with the belt is the rubber match against the man he just beat, not a tune-up and not a placeholder.

UFC 333 is the entire near-term bantamweight argument. Winner owns the throne. Loser drops into a contender queue that is already loud. Merab remains the immediate rematch case and the clearest No. 1 challenger on paper until someone else forces a different booking. Everything else at 135 is color until that trilogy lands — including the Song–O'Malley debate that will matter more the morning after Oct. 24 than it does while the rubber match is still ahead.

Contenders: Song, O'Malley, no consensus No. 2

Behind the title picture, there is no consensus No. 2. Song Yadong knocked out Umar Nurmagomedov in Shanghai on Aug. 29 — the hottest recent result in the division, and the case for putting Song next if the promotion wants the most recent statement win. Sean O'Malley still sits high after his Freedom 250 knockout and continues to campaign for the next slot if Yan retains — recent KO heat plus public volume, not a signed challenge. That split is the practical problem for whoever leaves Abu Dhabi with the belt: the next-challenger conversation will not be unanimous the morning after Oct. 24.

The class is not idle while the trilogy waits. Raul Rosas Jr. versus Raoni Barcelos is booked for Sept. 26. Deiveson Figueiredo versus Payton Talbott is on Oct. 3. Both are consequential for the mid-board; neither is a title eliminator on the published card. Those results can reshuffle who sits behind Song and O'Malley, but they do not rewrite the Oct. 24 title night. Yan is champion, Merab is the first defense, and Song's Shanghai knockout forced a real reordering debate with O'Malley. Until a date is printed after the trilogy, treat Song's knockout heat and O'Malley's post-trilogy talk as competing claims — not as signed challenges.