Teixeira (22-2) was wobbled twice in the opening round with Bader (15-4) but ultimately landed a devastating two-punch combo that sent his opponent crashing to the floor.
Fighting in his home state for the first time in his career, Teixeira struggled early on, as wrestling specialist Bader flashed his powerful striking abilities and staggered the Brazilian on two different occasions. But just as it seemed Bader was primed for victory, Teixeira landed a left-right combination that earned a knockdown.
Teixeira seized the opportunity and pounced with additional blows until referee Herb Dean called the fight at the 2:55 mark of the first frame.
He has now earned 20 straight wins and UFC exec Marshall Zelaznik confirmed at the evening's post-event press conference that Teixeira will challenge the winner of UFC 165's main event with light-heavyweight champ Jon Jones facing top contender Alexander Gustafsson in Toronto. Additionally, he earned the evening's US$50,000 "Knockout of the Night" bonus for his work.
"To tell you the truth, I wasn't happy with this fight," said Teixeira. "I was disappointed he was able to knock me down. … But I'm telling you, this belt is going to be mine. It doesn't matter if it's Jon Jones or Gustafsson. It's mine."
In the night's co-feature, former Strikeforce champion Ronaldo "Jacare" Souza (19-3) proved he's a legitimate contender at middleweight by scoring an incredible first-round stoppage of one-time title challenger Yushin Okami (29-8).
Souza, known for his grappling prowess, instead chose to box with Okami, and this risk paid dividends. Souza staggered Okami with an early right hand and used the same punch later in the round to send Okami crashing to the floor.
Souza followed to the canvas to seal the deal, earning the TKO win at the 2:47 mark of the opening round.
"I've got a very tough right hand," Souza said after the win. "Whoever the UFC wants me to fight, I'll fight."
Souza is undefeated in two UFC appearances and may soon find himself challenging for a UFC belt.
And in a flyweight feature, Joseph Benavidez (19-3) confirmed his status as the division's No. 1 contender by dominating fellow contender Jussier Formiga (15-3) en route to a first-round stoppage.
Formiga, a Brazilian jiu-jitsu ace, was unable to work inside in the early going and was forced to stand with Benavidez, who capitalized on the position. A two-punch combination stunned Formiga, and Benavidez followed with a knee to the body that sent his opponent to the floor.
Benavidez jumped on his fallen foe and landed additional strikes until the bout was called off at the 3:07 mark of the first.
Benavidez has won three straight fights since losing in a bid to unseat current champ Demetrious Johnson, but a rematch may soon be in order. For his part, Benavidez refuses to call for the fight, but his performances are starting to demand it.
"I'm not the kind of type to bark for a title shot," Benavidez said afterward. "I'm just trying to get better every day, every fight. But I think I've proven that I can beat and finish the top guys in the division. So whatever the UFC wants to do, I respect that, and I'll be ready to do it."
UFC Fight Night 28 drew a reported attendance of 5,126 according to Zelaznik. While the total was significantly lower than past events in Brazil, Zelaznik said he was happy with the turnout for a Wednesday night-event, which he said the company will continue to view as more "intimate" fight cards.