LAS VEGAS — Kayla Harrison’s UFC debut could not have been any better.

The former two-time Olympic judo champion dominated former champion and combat sports legend Holly Holm, beating Holm with a rear-naked choke submission at 1 minute, 47 seconds of the second round Saturday on the prelims of UFC 300 at T-Mobile Arena.

“By the end of the year, I will be UFC champion,” Harrison said in her postfight interview.

Harrison, who was cutting to bantamweight for the first time in her MMA career, took Holm down in the first round and blasted her with hard ground and pound, including elbows. Those elbows were a major factor in the fight. Harrison was not able to use those in PFL, where she previously fought due to that promotion’s rules. Harrison was a two-time PFL women’s lightweight champion.

The second round was more of the same. Harrison went for a head kick and then shot in for a takedown, which succeeded. She grabbed for a guillotine choke, which Holm defended. But then she landed a judo trip, got Holm’s back and sunk in the rear-naked choke for the victory.

Harrison (17-1) was coming off a unanimous decision win over UFC veteran Aspen Ladd under the PFL banner back in November. The Ohio native, who lives and trains in Florida, has only lost once in her career, to Larissa Pacheco in 2022. Harrison has also beaten Pacheco twice. Harrison, 33, had 13 finishes in 18 pro fights.

In PFL, Harrison fought mostly at 155 pounds and she competed in the Olympics at around 172 pounds. One of the biggest tests for her was making 135 pounds, which she needed to do in order to come to the UFC. Harrison successfully made the weight Friday.

Holm (15-7, 1 NC) had just one loss in her last five fights coming in. The Albuquerque, New Mexico native famously knocked out Ronda Rousey to win the UFC women’s bantamweight title in 2015. Rousey and Harrison were former judo teammates. Holm, 42, had a career in boxing before converting to MMA and is in the International Boxing Hall of Fame.