UFC 331 books Arman Tsarukyan vs. Mauricio Ruffy as five-round lightweight co-main

UFC 331 has found its next lightweight co-main attraction. The organization has booked Arman Tsarukyan to face Mauricio Ruffy on September 19 Arena in Los Angeles, with the fight set for five rounds. The matchup positions Tsarukyan for a high-profile runway back into the division’s title conversation, while it gives Ruffy a chance to reset after a setback, according to the reporting that surfaced alongside the booking announcement.

The timing is notable. Tsarukyan’s return comes after a long layoff, a pause that often changes a contender’s rhythm, training timing, and sense of urgency. In the lightweight landscape, where matchups are regularly tied to momentum, a return fight at co-main level carries added weight because it can reframe how quickly a fighter gets back to the front of the queue.

Ruffy, meanwhile, enters the matchup looking to rebound. A co-main assignment after a loss can serve as both a proving ground and a pressure test, especially in a division where title opportunities can narrow rapidly. With a five-round format scheduled, the fight is set up to showcase sustained grappling, striking volume, and late-fight adjustments rather than short bursts.

The booking also clarifies what had been a shifting storyline in the days leading up to the announcement. Tsarukyan had been linked in speculation to a potential rematch with former champion Charles Oliveira, but UFC’s decision to pair him with Ruffy redirects attention toward a different path back to the title picture.

UFC 331’s location adds another layer. Arena has become a frequent venue for major UFC cards in the Los Angeles market, and fight-night stakes at a co-main level tend to rise when the spotlight is on a contender’s return. For Tsarukyan, the question is whether he can translate time away into sharp, fight-ready urgency against an opponent aiming to respond to adversity. For Ruffy, the focus will be on turning a setback into a statement performance that keeps him relevant at the top end of the weight class.

What to watch next is how the fight matchup shapes both men’s immediate trajectories. Tsarukyan’s long layoff and co-main placement suggest the UFC intends him to matter right away. Ruffy’s rebound opportunity, paired with the five-round distance, sets up a contest where durability and tactical control could define the outcome. Until additional bout details are officially released and confirmed, the broader card context remains the main missing piece for fans tracking how UFC 331 is being built.