Dillashaw lands only 0.56 knockdowns per 15 minutes and Garbrandt had never been knocked down in his UFC career.
"This is a dream come true, from Olympic gold medallist to UFC champion", Cejudo said.
Cejudo will make his second bid for the UFC flyweight title pegged as a +350 underdog on the UFC 227 odds after picking up wins in his past two outings, including a second-round TKO win over Wilson Reis last September at UFC Edmonton that earned him his first Performance of the Night bonus since joining the UFC in 2014.
But the crucial difference was clear to see as Dillashaw kept his defences tight, while Garbrandt left his chin wide open, and the defending champ dropped him with a huge shot.
In a thrilling conclusion to UFC 227 on Saturday night, TJ Dillashaw (17-4) retained his UFC Bantamweight belt with a first-round technical knockout of rival and former teammate Cody Garbrandt (11-3).
Dillashaw closes this chapter with 2 wins and a championship belt still around his waist.
After his historic flyweight title win, Cejudo said he wanted a crack at the bantamweight title next, and a shot at the night's main event victor.
"He's a very dominant champion", Dillashaw said. "And the victor of this next bout, I wanna fight that guy".
After the result, Dillashaw welcomed a challenge by newly crowned flyweight champion Henry Cejudo.
The fight didn't start out in Cejudo's favor as he appeared to turn an ankle in the opening round and limped at times as Johnson continued to switch stances and score with strikes from the outside.
Two years after losing to flyweight champion Demetrious Johnson via first-round TKO, Henry Cejudo was set on showing the world just how much he had improved.
Cejudo didn't have it all his own way, however, as Johnson utilised leg kicks in typically clinical fashion to test the resilience of his challenger.
The 12-fight event takes place at the Staples Center in Los Angeles and kicks off with three bouts streaming on UFC Fight Pass at 6:30 p.m. ET. The luminaries at cageside included Matt Damon, Chris Pratt, Miles Teller, Mickey Rourke and Zlatan Ibrahimovic.