Johnson (25-2) defended the UFC flyweight championship for the ninth consecutive time at The Ultimate Fighter 24 Finale on Saturday, defeating Tim Elliott via unanimous decision. All three judges scored it for Johnson: 49-46, 49-46, 49-45.
The win moves Johnson into a tie with St-Pierre for the second-longest title reign in UFC history. He is just one away from tying the all-time record of 10, held by former middleweight champion Anderson Silva.
The victory was mostly a foregone conclusion for Johnson, with the major exception the opening round. In the first, Elliott locked in a guillotine and then transitioned to a D'Arce choke. The submission looked tight, but Johnson gave a thumbs up to the referee.
"I wasn't going out," Johnson said. "I said, 'Hey, hey, hey, [referee Herb Dean], don't you stop this fight.' And he said, 'I got you dog.'
"He blitzes on you. I stayed composed like a champion. I knew my grappling would be the best way to beat him."
In addition to the choke, Elliott dropped Johnson with a left hand later in the round. Despite that strong start, it was Johnson's fight from that point on. Elliott showed heart and drew a positive response from the crowd with his unorthodox striking but was badly outwrestled.
According to Fightmetric, Johnson was credited with five of six takedowns and a whopping 16:52 of control time. He spent the majority of the fight in top position, landing short punches and elbows and hunting submissions.
He threatened Elliott with rear-naked chokes in several rounds and appeared to have it locked up in the fourth. Johnson had his hooks in and the right arm under the neck, with Elliott grimacing. Somehow, the challenger wriggled out.
Elliott also stayed very active from the bottom, landing enough elbows himself to keep things competitive. He created several scrambles but ultimately forfeited dominant position to Johnson too often to turn the tide.
The matchup was unique in that Elliott, 29, was not publicly revealed as Johnson's opponent until Wednesday. Elliott earned the shot by winning the 24th season of "The Ultimate Fighter." The UFC actually cut Elliott in 2015 after he lost three in a row.
"Man, I know I can get in there with anybody and compete," Elliott said. "Even this fight, even though I was down when the time ran out, if it's a fight to the death, I beat everybody."
ESPN.com ranked Johnson the No. 1 pound-for-pound fighter in the world coming into the event. A Washington-based fighter, he has not lost since 2011. His only loss in the UFC came at 135 pounds to current bantamweight champion Dominick Cruz.
Johnson's next challenge will likely come in the form of Joseph Benavidez, whom he has defeated twice, in 2012 and 2013. Benavidez won his sixth straight fight Saturday by defeating Henry Cejudo by split decision.