UFC BJJ 13: 7 Facts on 2 Vacant Titles

Ronaldo Junior beat William Tackett by unanimous decision at UFC BJJ 4 last December, then needed surgery he couldn’t put off any longer, and that’s the only reason Tackett is getting a second shot at the middleweight title he lost on the scorecards. Ten months later, on October 29, he gets Jay Rodriguez instead of a rematch — an ADCC silver medalist who has never set foot in a UFC BJJ bout. Across the same card, two-time IBJJF world champion Jalen Fonacier defends the fastest finish in UFC BJJ history against a total unknown who won his way in through the promotion’s open tournament series. Both of UFC BJJ’s biggest prizes are up for grabs the same night, and neither champion lost in the cage to get there.

What’s Actually at Stake at UFC BJJ 13

Most UFC BJJ cards crown a challenger or defend a champion. UFC BJJ 13 does neither — it fills two seats that emptied out for reasons that have nothing to do with a loss. Ronaldo Junior’s middleweight reign ends on a medical table, not a mat. Mikey Musumeci’s bantamweight reign ends because the sport’s most decorated active competitor decided, at 30, that he’d rather chase an MMA debut than keep defending a belt he’s already proven he can hold. Both vacancies hand opportunities to fighters who, on paper, had no obvious claim to a title shot three months ago.

That’s the part worth sitting with before the heel hook and choke breakdowns start. Jay Rodriguez has zero UFC BJJ fights. Kleber Barbosa has zero UFC BJJ fights. Both are walking straight into a championship main card the first time the promotion puts them on camera, and both earned it without beating the man who used to hold the belt. That’s a genuinely unusual structure for a combat sports title fight, and it’s exactly why this card deserves more attention than its billing as a regular Thursday night at Meta APEX suggests.

William Tackett vs. Jay Rodriguez: A Rematch That Isn’t One

Tackett came into UFC BJJ 2 already a decorated colored-belt standout — four gold medals and three silvers across the IBJJF Pan and World Championships before he ever earned his black belt in March 2021. He opened his UFC BJJ account with a first-round rear naked choke over Kyle Chambers, the kind of finish that made the middleweight title fight against Ronaldo Junior five months later feel like a formality. It wasn’t. Ronaldo pushed a full 15 minutes of pace, took the back, and worked an arm triangle into an anaconda combination that never quite closed but never let Tackett breathe either. Three judges scored it the same way: Ronaldo Junior, unanimous decision, inaugural champion.

Tackett’s overall competitive record sits at 63-23, a 70% submission rate across his wins, and his most dependable finish — the rear naked choke — appears nine times on his résumé. He’s also comfortable going to the legs when the back isn’t there: five calf slicer finishes, three heel hooks. That range matters against Rodriguez, a converted folkstyle wrestler who built his jiu-jitsu career almost entirely in no-gi grappling and has faced far less finishing pressure from the choke than from the leg lock game that dominates the sport right now. Watch for Tackett to hunt the back early rather than engage Rodriguez’s wrestling scrambles on the feet, where the stronger folkstyle base evens the fight out fast.

Why Jay Rodriguez Is the Most Dangerous Newcomer on This Card

Rodriguez didn’t come up through a kids’ program. He wrestled scholastic and folkstyle through high school, picked up BJJ in September 2020 at Studio 84 in New Jersey under Jay Regalbuto, and trained twice a day — a pace that got him to blue belt in seven months. By mid-2021 he’d relocated to Austin to train full-time at the newly formed B-Team alongside his older brother, Nicky Rodriguez, already one of the sport’s recognizable names. The wrestling base shows up constantly in his matches: scrambles that other black belts can’t escape, and a willingness to grind rather than hunt a single highlight-reel finish.

His signature result came at blue belt, when he won the 2022 ADCC United States Qualifier — an almost unheard-of outcome at that rank. He backed it up two years later with a silver medal at the 2024 ADCC World Championship at -88kg, losing the final 9-0 to Giancarlo Bodoni but beating a stacked bracket to get there. A silver at ADCC, the sport’s most competitive no-gi tournament, is a heavier credential than anything else on this card besides Tackett’s own résumé. Rodriguez enters UFC BJJ with zero cage reps and one of the best wrestling bases in the promotion’s short history. That combination is exactly what makes him dangerous instead of just a name plugged into an empty title slot.

Jalen Fonacier vs. Kleber Barbosa: Grappling for a Vacant Throne

Musumeci didn’t lose this belt. He vacated it on October 9, three weeks before this card, saying flatly that he’s “obsessed with training MMA” at 30 years old and wants to prioritize it, while leaving the door open to return to grappling “anytime.” That’s a jiu-jitsu legend walking away from a title he was never beaten for — and it opens the door for his own training partner to inherit the division.

Fonacier is a two-time IBJJF world champion who’s gone a perfect 4-0 inside UFC BJJ, and he already owns the fastest submission in the promotion’s history — a heel hook finish against Carlos Oliveira at UFC BJJ 5 that barely gave the broadcast time to show a replay. He’s Musumeci’s teammate, which means he’s trained alongside the exact style he now inherits the title from rather than against it. That’s a real edge heading into a fight where his opponent is a complete question mark, and it’s the single biggest reason oddsmakers will likely favor Fonacier heavily despite Barbosa’s own gi and no-gi résumé.

Barbosa’s Leap From the Opens to a Title Shot

Kleber Barbosa is the biggest wild card UFC BJJ has put in a title fight since the promotion launched. He’s a black belt under Isaque Bahiense who built his reputation almost entirely on the IBJJF gi and no-gi circuits — a runner-up finish at the 2025 IBJJF No-Gi World Championship and a 36-win competitive record heading into his rookie black belt year. None of that happened in front of a UFC BJJ camera. His invitation came through UFC BJJ Opens, the promotion’s open-entry tournament series built specifically to surface competitors outside its usual pipeline of established pros, and he won it outright — earning an immediate title shot with zero prior UFC BJJ tape for Fonacier’s camp to study.

That cuts both ways. Barbosa is walking into the brightest lights of his career against a four-fight UFC BJJ veteran with the fastest finish in company history, and he’s doing it with none of the live-reps experience Fonacier already has under these exact rules and this exact format. But a competitor with 36 wins and a runner-up finish at an IBJJF World Championship isn’t a theoretical opponent either. If Barbosa’s scrambles hold up against someone actively hunting a heel hook the moment the fight hits the mat, the Opens pipeline just produced UFC BJJ’s biggest underdog story to date.

What a Win Actually Changes for Each Fighter

For Tackett, beating Rodriguez doesn’t erase the loss to Ronaldo Junior — it just means he’s champion while the man who beat him is on the sideline recovering from surgery. That’s an awkward kind of title, and the rematch question doesn’t go away just because Ronaldo’s name isn’t on this card. For Rodriguez, a win instantly makes him the biggest story in the middleweight division: a debut title in a sport where most fighters need three or four UFC BJJ appearances before they sniff a championship slot. Fonacier solidifies himself as the first legitimate successor to Musumeci’s bantamweight run, while a Barbosa win turns UFC BJJ Opens into the most credible path into a UFC BJJ title picture the promotion has built so far — a precedent worth watching regardless of how this specific fight goes.

How to Watch UFC BJJ 13

UFC BJJ 13: Tackett vs. Rodriguez streams live on UFC Fight Pass Thursday, October 29, starting at 8 PM ET / 5 PM PT from Meta APEX in Las Vegas. The two title fights headline, with the full undercard announced closer to fight week. If the last three UFC BJJ cards are any indication, expect at least one leg lock finish and a scorecard that splits fans the way UFC BJJ 12’s did three weeks earlier — the promotion’s judging panel has drawn criticism on multiple cards this year, and a close decision in either title fight here would reopen that conversation fast.

There’s also a scheduling wrinkle worth flagging: this is UFC BJJ’s third event in four weeks, following UFC BJJ 12 on October 8 and the Pan No-Gi Championship results that dominated the same stretch. That pace is unusually aggressive even for a promotion that’s been expanding its calendar all year, and it puts real pressure on both new champions to be ready for an immediate turnaround if the UFC BJJ team books a defense before year’s end.

No-gi grappling at this level comes down to inches and grips held a half-second longer than your opponent expects — the same margins that separate a rashguard that stays put from one that bunches up mid-scramble. Whatever you’re training in while you watch this one, it should move with you, not against you.

Sources

• UFC BJJ 13 — Tackett vs Rodriguez event listing — AXS, event date, venue, and championship bout details
• Mikey Musumeci drops UFC BJJ title to ‘prioritize’ MMA — MMAmania, on the bantamweight title vacancy
• Ronaldo Junior: Sky’s the Limit — UFC.com, on winning the middleweight title from William Tackett
• William Tackett fighter profile — BJJ Heroes, competitive record and submission breakdown
• UFC BJJ 12’s Leg Lock Night Ends in Scorecard Controversy — RashguardGuy, the previous UFC BJJ event