AMES, Iowa -- Trevone Boykin scored on a 1-yard TD run with 38 seconds left and TCU rallied to beat Iowa State 21-17 on Saturday and snap a three-game losing streak.
Boykin ran for three touchdowns for the Horned Frogs (4-6, 2-5 Big 12), who remain in contention for possible bowl eligibility with two games left.
The Horned Frogs went 58 yards in just 1:56 -- a drive keyed by a 22-yard run from Aaron Green on 4th-down-and-1 -- and took a four-point lead on their only score of the second half.
Grant Rohach threw for 148 yards for Iowa State (1-8, 0-6), whose last-ditch effort ended near midfield. The Cyclones have lost six straight.
Casey Pachall threw for 245 yards for TCU.
But he also nearly threw the game away midway through the fourth quarter.
Pachall drove TCU from its own 1-yard line to the Iowa State 23 with consecutive completions to Brandon Carter and LaDarius Brown. But Jevohn Miller drilled Carter on a third-down play to force out the ball, and Jeremiah George's interception kept the Horned Frogs from a potential game-tying field goal.
Iowa State gave TCU one last chance at its own 42-yard line with 2:34 to go after a poor punt from Kirby Van Der Kamp.
Green's 22-yard run put the Horned Frogs at the Iowa State 27. He later got them to the 3-yard line with a 17-yard run, setting up Boykin's game-winner.
Green finished with 72 yards on 19 carries.
The Cyclones went into halftime trailing for the fourth game in a row.
DeVondrick Nealy brought Iowa State even with one of the team's biggest plays of the season.
Nealy broke a pair of tackles en route to a 98-yard kickoff return -- second-longest in school history -- to open the second half.
That return sparked the Cyclones, who took their first lead in a month, 17-14, on Cole Netten's 35-yard field goal late in the third quarter.
But Iowa State finished with just 283 yards on 82 plays.
The Cyclones had a gusty wind at their backs to open the game -- and gained just 15 yards during four consecutive three-and-out drives.
But Van Der Kamp gave the Cyclones a spark with a 25-yard completion to Justin Coleman on a fake punt. Iowa State then put in Richardson, and he took his first snap 15 yards to tie the game at 7-7.
TCU answered immediately. A 33-yard completion from Pachall to Carter was upheld after an Iowa State challenge, and Boykin's second carry of the game resulted in his second TD, a 3-yarder that made it 14-7 Horned Frogs with 9:51 left in the first half.
Boykin, who opened the scoring with an 18-yard TD run, also had four catches for 24 yards as the Horned Frogs bounced back from a brutal overtime loss to West Virginia with their first road win.
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Ohio State remained No. 1 in the AP Top 25 and tied a poll record Sunday despite lagging support from voters. Meanwhile, No. 2 TCU and No. 3 Baylor edged forward and No. 4 Michigan State slipped.
Texas cornerback Kris Boyd has apologized for retweeting a Texas A&M fan during halftime of Texas' 50-7 loss to TCU on Saturday.
The Big 12 on Sunday acknowledged an officiating mistake that incorrectly awarded Oklahoma State a first down Saturday and said the officials involved would be disciplined.
Georgia coach Mark Richt says he's sticking with Greyson Lambert, who was just 10-for-24 for 86 yards in a loss to Alabama, as the Bulldogs starting quarterback.
Will Grier threw four touchdown passes to four receivers -- all in the first half -- and No. 25 Florida downed third-ranked Mississippi 38-10 on Saturday night.
Leonard Fournette highlighted his SEC-record third straight 200-yard game with a 75-yard touchdown run, and No. 9 LSU overcame Eastern Michigan 44-22 on Saturday night.