Teixeira gave it all back and then some. He landed huge overhand rights and left hooks, took Prochazka down and opened up a gnarly cut with an elbow.
Both men took a career's worth of punishment in one of the most grueling, back-and-forth fights in MMA history. In the end, somehow, Prochazka grabbed on to an orthodox rear-naked choke in the final seconds and finished Teixeira via submission at 4:32 of the fifth and final round Saturday in the main event of UFC 275 in Singapore.
With the victory, Prochazka became the UFC light heavyweight champion. It was his first submission victory in UFC and first overall since 2014. It was Teixeira's first career submission loss.
"It was a true war," Prochazka said. "Glover is a true warrior. And I like that."
Coming into the fight, ESPN had Teixeira ranked No. 8 on its list of the best pound-for-pound MMA fighters in the world. Teixeira was ranked No. 1 and Prochazka was No. 4 at light heavyweight.
Prochazka's submission was the second-latest finish in UFC championship history, behind Demetrious Johnson's 2015 armbar victory over Kyoji Horiguchi with just one second left in the fight. Prochazka is the first male fighter to win an undisputed UFC title within his first three fights since Brock Lesnar in 2008, according to ESPN Stats & Information.
Had Teixeira held on until the final bell, he would have won or the result would have been a split draw with Teixeira retaining the title. Judge Michael Bell had it 38-38 going into the fifth round, judge Ben Cartlidge had Teixeira up 39-37, and Clemens Warner had Teixeira ahead 38-37.
"I gave my all," Teixeira said. "Live by the sword, die by the sword."
It certainly was not an easy fight to judge, with more twists and turns than an M. Night Shyamalan movie.
Teixeira looked early like he would run over Prochazka with his superior wrestling and grappling. Teixeira took Prochazka down several times in the first round, got into mount and landed hard shots from the top position. Prochazka, though, was able to shuck Teixeira off his back near the end of the round and land hard ground-and-pound exchanges on the canvas.
Prochazka took that momentum into the second round and landed some big punches, a knee and ground-and-pound with Teixeira on the mat. But back on the feet, Teixeira caught Prochazka pressuring forward wildly with a left hook that dropped him. Teixeira ended up mounting Prochazka again and landing an elbow that opened up a huge cut over Prochazka's left eye.
In the third, Prochazka once again dominated the opening minutes with his creative striking, landing left hands, knees and hard shots to the body. Prochazka got Teixeira down and was landing hard punches from the top but then went for an ill-advised arm-triangle choke, which Teixeira countered to get on top. From there, Teixeira went on the offensive, landing punches.
"He was hitting me with body shots that took my gas away," Teixeira said. "I was gassed out, to be honest."
Teixeira hurt Prochazka with a left hook in the fourth round and then took him down again. He landed shots from the top and worked for an arm-triangle choke but could not get it. Prochazka managed to roll out as Teixeira passed to the side in an attempt to complete the choke. At that point, both men's faces were covered in blood. Prochazka landed some punches from the top, but Teixeira somehow swept and took Prochazka's back before the end of the round.
In the fifth, Teixeira, though tired, came out firing. He blasted Prochazka with an overhand right into a combination. And then he made his own strategic error, going for a guillotine choke. Prochazka slid out of it and ended up on top. Back on the feet, both men landed hard shots, with Teixeira getting the better of things. Teixeira got Prochazka on his back again and took mount with about 1:51 left in the fight.
Teixeira landed a hard elbow from mount, but Prochazka used his legs to kick off the cage and escape the position. Prochazka ended up on the side of Teixeira's back with Teixeira on all fours. From there, Prochazka brought his arms up into a rear-naked choke around Teixeira's neck. Teixeira tried to escape by diving forward but ended up tapping out. Prochazka never even got his legs around Teixeira -- in grappling terms, he never got his hooks in -- during the opportune, unorthodox choke.
"I'm ready to end it first or fifth round, doesn't matter," Prochazka said. "Doesn't matter which technique. ... That came naturally. I just watched the moment, what opportunity is before me."
Prochazka (29-3-1) has won 13 straight, including his first three in UFC. The Czech Republic native has finished 11 in a row.
The 29-year-old Prochazka was coming off a second-round spinning back elbow knockout of Dominick Reyes in May 2021, a knockout of the year contender. "Denisa" is the former light heavyweight champion of Japan's Rizin Fighting Federation promotion.
Teixeira (33-8) became the oldest first-time champion in UFC history when he beat Jan Blachowicz for the title at UFC 267 in October. The Brazil native was the second-oldest UFC champion ever, behind Randy Couture. Teixeira, 42, had a six-fight winning streak snapped Saturday. He had discussed retirement earlier this year but vowed to continue fighting afterward.
"Do I look 42 out there?" Teixeira said in the Octagon afterward. "Then, I'm gonna keep going."