KANSAS CITY, Mo. — A sudden surge of energy got the Kansas State Wildcats back on track.

Xavier Sneed made sure they stayed there.

Shaking off a lethargic start and an early 12-point deficit, the No. 15-ranked and top-seeded Wildcats regrouped to pull within two at halftime and turned on the jets in the second period Thursday afternoon to bury TCU 70-61 in their Big 12 Tournament quarterfinal at Sprint Center.

And nobody turned things around more dramatically than Sneed, the Wildcats' 6-foot-5 junior wing. His 3-pointer at the buzzer not only mitigated an otherwise forgetful first half, but served as just the spark he and K-State needed after intermission.

"I thought me yelling at him might have set him off a little bit," K-State coach Bruce Weber said with a smile after Sneed proceeded to finish with 19 points, 7 rebounds and 5 assists. "But he definitely stepped up and made some big plays."

With the victory, K-State improved to 25-7 and will play No. 5 seed Iowa State (21-11) in Friday's 6 p.m. semifinal.

While seldom-used sophomore post Levi Stockard provided a surprise scoring burst in the absence of injured all-conference forward Dean Wade in the first period, and the return of sixth man Cartier Diarra clearly energized the Wildcats throughout, it was Sneed's second-half performance that took them to the finish line.

The 3-pointer before the buzzer was Sneed's first basket of the game after four straight misses.

"Just keep shooting," Sneed said of his approach. "Shooters shoot. That's what they keep telling me. Coach and Barry (Brown) kind of lit a fire under me at halftime to step it up and (play) a bigger role."

He did, to the tune of 5 for 7 overall in the second half, 3 of 5 from 3-point range. Perhaps the shot of the game was his second buzzer-beater, a top-of-the-key 3 as the shot clock hit zero with 56 seconds remaining, doubling K-State's slim three-point advantage to 66-60.

"I was on the right wing and I saw the clock dwindling down and I was yelling for him to shoot," Brown said. "I didn't know if he saw the shot clock."

Sneed, who momentarily bobbled the ball before gathering himself, had no choice but to let it fly.

"Looking at the clock, I knew I had to get a shot off. I made a move and (the defender) kind of bit for one of the moves, so I just knew I had to get it up quick, and it was a good shot and it went in.

"It was definitely a dagger. It put us up six with under a minute to go."

In the end, the Wildcats recovered from an ugly opening 10 minutes to finish with four players in double figures, as Brown added 12 points and six assists, Makol Mawien 10 points and eight rebounds and Kamau Stokes 10 points.

And, of course, there was the ever-present defense that forced 18 turnovers — nine in each half — and led to 22 points.

"We know we're a great offensive team when we get defensive stops and push it in transition," said Diarra, who had missed the eight previous games with a broken finger on his left (shooting) hand. "When you get a steal, push it.

"You get an advantage break and get easy baskets so you don't have to work so hard on offense."

Add an 18-12 edge in fast-break points to the 22-4 advantage off turnovers and 12-6 margin in second-chance points and it was a winning formula.

"We played well the first half and did some good things, but eventually the turnovers got to us," said TCU coach Jamie Dixon, whose Horned Frogs fell to 20-13.

TCU was led by Desmond Bane with 16 points, Alex Robinson with 12 points and seven assists — plus six turnovers — and Kevin Samuel with 11 points.

The Horned Frogs got off to a fast start as K-State struggled to get in sync offensively and led 23-11 on two Kendric Davis free throws with 9:05 left in the first half. But the Wildcats answered with a 10-2 spurt that included two Brown 3-pointers and a put-back and layup by Stockard, who had played a total of one minute the previous three games.

"He was very important," Stokes said of Stockard, who hit four of his five shots, all in the first half, to tie a season and career high with eight points. "Coach talks about guys stepping up and Levi stepped up today and he gave us post presence, and defensively he did a pretty good job."

Diarra, who had not played since Feb. 9, provided 8 points, 5 rebounds and 3 assists in 29 minutes off the bench.

No. 15 KANSAS ST. 70, TCU 61

TCU (20-13)

Noi 2-8 4-4 8, Miller 3-7 1-3 8, Samuel 4-5 3-5 11, Robinson 5-14 0-0 12, Bane 7-11 0-0 16, Nembhard 1-3 0-0 2, Davis 1-4 2-3 4. Totals 23-52 10-15 61.

KANSAS ST. (25-7)

Mawien 4-7 2-3 10, Trice 0-0 0-0 0, Sneed 6-12 3-4 19, Brown 5-16 0-0 12, Stokes 4-13 1-2 11, Muldoon 0-0 0-0 0, McAtee 0-0 0-0 0, Love 0-0 0-0 0, Stockard 4-5 0-0 8, Shadd 0-0 0-0 0, Neal-Williams 0-0 0-0 0, Diarra 2-7 4-6 8, McGuirl 1-2 0-0 2. Totals 26-62 10-15 70.

Halftime — TCU 34-32. 3-Point Goals — TCU 5-17 (Bane 2-3, Robinson 2-5, Miller 1-2, Nembhard 0-1, Davis 0-1, Noi 0-5), Kansas St. 8-25 (Sneed 4-8, Brown 2-7, Stokes 2-7, McGuirl 0-1, Diarra 0-2). Fouled Out — None. Rebounds — TCU 35 (Robinson, Noi, Miller 7), Kansas St. 33 (Mawien 8). Assists — TCU 13 (Robinson 7), Kansas St. 17 (Brown 6). Total Fouls — TCU 18, Kansas St. 16. A — 18,930 (18,972).