It was Kansas' second-largest loss at home under Self. The Jayhawks fell 84-59 to Texas on Jan. 2, 2021.
"The way they chewed gum. The way they tied their shoes. Everything they did was perfect today," Self said of TCU. "They played great. They're so fast. They're so athletic off the bench. Their bench was unbelievable. ... That was a beatdown."
The loss snapped a 16-game winning streak at home for Kansas. The Jayhawks (15-3, 5-2 Big 12), who lost 83-82 in overtime at Kansas State on Tuesday, had not lost consecutive games in the state since 1989, when it had home losses on Jan. 28 to K-State and on Feb. 1 to Missouri.
Kansas trailed by 10 at halftime and never closed the gap within single digits. TCU extended the lead to as many as 24 points. The Jayhawks shot only 32.1% in the second half.
"I thought we were playing like there was a 10-point play in our back pocket," Self said. "That happens a lot when you get behind."
"Obviously it was a great win for our program,'' TCU coach Jamie Dixon said. "What I'm most proud of [was] how we responded. We didn't play very well the other day (in a 74-65 loss at West Virginia). But we responded.
"I'm really proud of our bench. I don't think I've done a great job of getting them ready. I knew they were good, and we had to get them in their groove.''
TCU entered the game with an 0-17 record in road games vs. AP top-five opponents.
Jalen Wilson led Kansas with 30 points. He was coming off a career-high 38 on Tuesday against K-State. Kevin McCullar with 10 points was the only other Jayhawk in double figures.
Wilson, according to ESPN Stats & Information, became the first Kansas player to score at least half of the team's points in a game since the Big 12 was formed in 1996.
TCU's Eddie Lampkin was hobbled late in the first half with what was later called a high left ankle sprain. He returned and finished with 8 points and 4 rebounds.
TCU used a 19-0 run early in the first half to open a 33-13 lead, forcing Self to use three of his four timeouts in the first 9:10 of the half. The Horned Frogs hit 13 of their first 15 shots. They finished the half shooting 58.6% (17-of-29).
"This team has done really well and caught some good fortune doing it well," Self said. "This league is so good that if you can't make other people play poorly, you're not going to have a lot of success."
Kansas trailed by as many as 22 points (37-15) before going on an 11-0 run. The Frogs led 48-38 at halftime, the closest Kansas had been since early in the big TCU run.
Kansas stayed in the game thanks to 21 first-half points by Wilson. He picked up his second foul with 2:13 left in the half. He returned for the final possession and hit a baseline jumper with 5 seconds left.
TCU: The Horned Frogs will host Oklahoma on Tuesday night before traveling to Starkville to play Mississippi State in the SEC/Big 12 Challenge next Saturday.
Kansas: The Jayhawks have a matchup with Baylor in Waco, Texas, on Monday before heading to Lexington to face Kentucky in the SEC/Big 12 Challenge next Saturday.
The Associated Press contributed to this report.