Amid a swarm of fans celebrating No. 25 Iowa State's 14-7 upset win over No. 4 TCU on Saturday, second-year Cyclones coach Matt Campbell took in the atmosphere at Jack Trice Stadium in Ames, Iowa, with a look of pride.

"That's why we came here, to win games like this," said Campbell, who previously resurrected Toledo's program. "You look at this stadium, you look at this crowd and we knew we could do something special here. Boy, I'm really proud of our kids."

The Horned Frogs (7-1, 4-1 Big 12) entered the game with the press clippings on defense, but the Cyclones (6-2, 4-1) showed dominance of their own, shutting out TCU's offense.

TCU managed a season-low in points and had almost as many penalties (11 for 104 yards) as first downs (14). The Horned Frogs' only touchdown came on a 94-yard kickoff return by KaVontae Turpin to open the second half.

Iowa State has allowed only two offensive touchdowns in its last three games.

"The key to our defense is staying together and trusting each other and not allowing the pressure to get to us," said linebacker Marcel Spears, who thwarted TCU's last possession by intercepting quarterback Kenny Hill's pass at the Iowa State 44.

Iowa State has defeated two top-five teams this season after starting 2-2. The Cyclones defeated then-No. 3 Oklahoma in Norman, Okla., on Oct. 7. Saturday's win snaps an 11-game losing streak to ranked opponents at home, dating to a 37-31 double-overtime win over No. 2 Oklahoma State in 2011.

"First off, give Coach Campbell a lot of credit," TCU coach Gary Patterson said. "We didn't score on offense. We got down there (failing to score after reaching the red zone twice in the second half) and they made the plays. We didn't."

Iowa State went into halftime with a 14-0 lead behind two touchdown passes by former walk-on quarterback Kyle Kempt, who is 4-0 as a starter after replacing Jacob Park going into the Oklahoma game. Kempt completed 21 of 35 pass attempts for 202 yards.

His touchdown passes in the first half concluded sustained drives against TCU, which ranked first in the Big 12 and 11th nationally in total defense (291.3 yards per game) entering the game. The Cyclones had 215 yards by halftime but finished with only 255 after the Horned Frogs adjusted.

Kempt's 17-yard touchdown pass to Matthew Eaton with 7:45 left in the first quarter capped a nine-play, 85-yard drive.

His 4-yard scoring strike to Hakeem Butler, who barely managed to get a foot down at the back of the end zone, ended an 11-play, 82-yard drive.

Hill threw an interception in the end zone after the Horned Frogs drove to the Iowa State 7-yard line midway through the third quarter. Cornerback Brian Peavy returned the interception to the TCU 30.

"You have to at least make field goals when you get down there and we didn't do that," Patterson said. "This is not what we wanted. We have to start with the staff. We have to put our guys in the right position to win and then they have to play."

Kempt -- who was intercepted in the Cyclones' previous possession -- threw what appeared to be another interception that was returned 77 yards to the end zone by TCU strong safety Ridwan Issahaku with 7:27 left in the third quarter. The play was called back, however, because of an offsides penalty against defensive end Mat Boesen.

With 7:11 left in the fourth quarter, Hill fumbled away the ball after TCU drove to the Iowa State 3. Defensive end Jason Waggoner recovered the ball at the Horned Frogs' 15-yard line on the sack. Hill finished 12 of 25 passing for 135 yards.

Darius Anderson led the Horned Frogs with 95 yards on 12 carries. David Montgomery led Iowa State on the ground with 74 yards on 25 carries.

NOTES: The game was the first featuring two AP Top 25 teams at Jack Trice Stadium since 2002, when No. 19 Iowa State defeated No. 20 Nebraska 36-14. ... Before Saturday, since 2000, TCU had the nation's best record (26-2, .929 winning percentage) when ranked in the top five. ... TCU is 23-20 against ranked opponents under coach Gary Patterson, including 9-6 over the last four seasons. ... Iowa State WR Allen Lazard leads active FBS players in consecutive games with a catch (43). Entering the game, Lazard ranked third nationally among active players in receptions (203), fifth in receiving yards (2,790) and tied for fifth in touchdown catches (21). Lazard caught six passes for 106 yards against TCU.