Tony Ferguson lacks only one piece to his career puzzle: the undisputed Ultimate Fighting Championship lightweight title.

Unbeaten since 2012, “El Cucuy” finds himself on a 12-fight winning streak that has him well-established as the clear-cut No. 1 contender for reigning UFC lightweight champion Khabib Nurmagomedov. A bout between the two men has been booked and canceled five times—some have begun to wonder if it will ever happen—for various reasons, the latest being the ongoing coronavirus pandemic. Ferguson, 36, last appeared at UFC 238 on June 8, when he forced a doctor stoppage against Donald Cerrone in between the second and third rounds. While his next move remains uncertain, he continues to be linked to blockbuster fights with Nurmagomedov and Justin Gaethje.

In a career already full of defining moments, here are five that stand out:

1. Ultimate Arrival

Ferguson added his name to a distinguished list that includes former UFC light heavyweight champions Forrest Griffin and Rashad Evans when he knocked out Ramsey Nijem in the first round of “The Ultimate Fighter” Season 13 welterweight final on June 4, 2011 in Las Vegas. A clean left hook dropped Nijem near the cage, and Ferguson polished off the Utah-based wrestler with a stiff right hand 3:54 into Round 1. Ferguson caught Nijem off-guard less than 20 seconds into the bout, as he scored with a takedown and took a dominant top position. The two ultimately returned to their feet, but the tone had been set. Nijem had one more Ferguson weapon about which to worry. Standing, Ferguson was the superior fighter by a considerable margin. He worked off his jab until the opening presented itself. The Californian fired a right hand that grazed the top of Nijem’s head and then landed the left hook that marked the beginning of the end. The fallen Nijem could not defend himself as the final punch fell.

2. A Menacing Experience

Michael Johnson took a brilliant strategic route against Ferguson and defeated “The Ultimate Fighter” Season 13 winner by unanimous decision in a UFC on Fox 3 lightweight showcase on May 5, 2012 at the Izod Center in East Rutherford, New Jersey. All three judges scored it the same: 30-27 for Johnson. “The Menace” set the tone midway through Round 1, as he momentarily stunned and dropped Ferguson with a stiff left hand. It was a harbinger of what was to come. Johnson attacked his counterpart’s arms, body and legs with blinding kicks and backed them up with one left hand after another, repeatedly snapping back Ferguson’s head. “El Cucuy” never found himself, overwhelmed by Johnson’s speed, aggression and firepower. He entered the cage on a six-fight winning streak and left it with stalled momentum, beaten for the first time under the UFC banner.

3. Groovy Comeback

Ferguson submitted the upset-minded Lando Vannata with a second-round brabo choke in the UFC Fight Night 91 co-main event on July 13, 2016 at the Denny Sanford Premier Center in Sioux Falls, South Dakota. A short-notice replacement for the injured Michael Chiesa, the previously unbeaten Vannata conceded defeat 2:22 into round two. Ferguson had a far more difficult time than most anticipated. Vannata wobbled “El Cucuy” with a spinning backfist and right cross in the first round, then set the 155-pound contender on skates with a beautifully timed head kick in the final minute. Ferguson was out on his feet but withstood the follow-up assault and forced the promotional newcomer into a second round. There, he snapped back Vannata’s head on multiple occasions, first with a crackling jab and later with a Superman punch he landed while springing off the cage. Soon after, Ferguson caught the Jackson-Wink MMA rep ducking in the center of the cage, ensnared him in a standing guillotine and then transitioned to the brabo choke before dragging him to the ground. Vannata struggled to free himself but had no choice but to tap.

4. Elite Confirmation

Former lightweight titleholder Rafael dos Anjos served as the vehicle for Ferguson completing his metamorphosis into a fully formed contender at 155 pounds. The Californian bested dos Anjos across five rounds and earned a unanimous decision in the UFC Fight Night 98 headliner on Nov. 5, 2016 at Mexico City Arena. Ferguson drew 48-47 marks from all three judges and walked away with his ninth consecutive victory—an all-time record for the division. Dos Anjos was game but could not match his adversary’s pace, output or creativity. The Brazilian left the Octagon with a cut near his right eye and damage to his nose, as he suffered back-to-back defeats for the first time in more than six years. Ferguson threw everything he had at the ex-champion, from hooks, leg kicks and uppercuts to spinning backfists, knees and standing elbows. “El Cucuy” connected on 74 more strikes (200-126) than dos Anjos. Ferguson also denied all five of the Rafael Cordeiro protégé’s takedown attempts.

5. Faux Gold

Ferguson laid claim to the interim when he submitted Kevin Lee with a triangle choke in the third round of their UFC 216 main event on Oct. 7, 2017 at T-Mobile Arena in Las Vegas. Lee capitulated 4:02 into Round 3, his five-fight winning streak having run its course. “The Motown Phenom” pushed Ferguson to the limit in the first round, where he delivered a takedown, climbed to mount and unleashed a torrent of punches and elbows. The barrage might have finished a lesser man. Ferguson shrugged. Lee’s pace slowed noticeably in the second, and he continued to deteriorate physically in the third. There, he executed two takedowns but lacked the energy to consolidate them with damage. Ferguson nearly tapped him with an armbar before catching the triangle and eliciting the tapout.