One of the biggest UFC fights of the year is now official.

Khabib Nurmagomedov and Justin Gaethje successfully weighed in Friday in Abu Dhabi, United Arab Emirates, for their UFC lightweight title unification bout. Nurmagomedov and Gaethje each weighed right at the limit of 155 pounds.

Nurmagomedov, the first fighter to hit the scale, stripped down naked to make the mark, needing the aid of a towel. He had his head in his hands and breathed a sigh of relief when he saw he had made weight.

Nurmagomedov, ESPN's top pound-for-pound fighter in the world, comes in as the undisputed UFC lightweight champion, while the No. 8-ranked Gaethje is the interim champ. The two will compete to unify the belts on Saturday in the main event of UFC 254 on Yas Island, which the UFC has dubbed "Fight Island."

ESPN has the undefeated Nurmagomedov ranked No. 1 in the world at lightweight, with Gaethje at No. 2.

Nurmagomedov (28-0), 32, of Dagestan, is 12-0 in the UFC and has rarely even lost a round. He owns wins over the likes of former UFC lightweight champions Conor McGregor and Rafael dos Anjos, as well as Dustin Poirier in his most recent bout at UFC 242 in September 2019.

Gaethje (22-2) has won four straight. The Arizona native is coming off an interim title victory with a fourth-round TKO over Tony Ferguson at UFC 249 on May 9. Gaethje, 31, is nicknamed "The Highlight" because of his exciting, all-action style. The former World Series of Fighting lightweight champion has not gone to decision in six years.

Former Bellator three-time lightweight champion Michael Chandler, newly signed by the UFC, weighed in Friday as a backup for the title fight. He made 155 pounds even.

The two co-main event fighters also successfully made weight ahead of UFC 254. Robert Whittaker, the former UFC middleweight champion, weighed 186 pounds, and Jared Cannonier hit the scale at 185 pounds. The Whittaker-Cannonier winner could be next for UFC middleweight champion Israel Adesanya.