FORT WORTH, Texas -Jeff Ballard and TCU couldn't pull off another comeback against BYU.
John Beck threw for 321 yards and three second-half touchdowns to lead BYU to a 31-17 victory Thursday night that ended No. 17 TCU's winning streak at 13 games. The streak was the longest in NCAA Division I-A.
BYU (3-2, 1-0 Mountain West) beat a Top 25 team for the first time since 1999, a stretch of 12 games since a victory over Colorado State. The Cougars went to double overtime at then-No. 23 Boston College earlier this month before losing 23-20.
TCU (3-1, 0-1) hadn't lost since a 21-10 defeat at SMU in the second game last season, a week after the Horned Frogs opened the 2005 season with an upset victory at Oklahoma.
Beck completed 23 of 37 passes just five days after sitting out a 38-0 victory over Utah State to rest both of his sore ankles. He threw a 40-yard TD strike to Michael Reed to start the second half, before a 26-yarder to Matt Allen, and Jonny Harlin's one-handed 4-yard grab with a defender on his back.
Ballard, who was 26-of-49 for 296 yards with a touchdown and an interception, lost for the first time in 12 starts as TCU's quarterback. He has started every game since after taking over late in the third quarter at BYU last September when the Frogs trailed by 16 points, then rallied to win 51-50 in overtime.
The Cougars went ahead 10-0 in the first half on consecutive long scoring drives, with a fumble by Ballard in between, and never trailed in the rematch.
It was the first Mountain West loss for the Frogs, who made their debut in the conference by sweeping through eight league games last season. They play again next Thursday against Utah, another team they beat in overtime last season.
TCU came one game short of tying the school record of 14 consecutive wins that included its undefeated national championship team in 1938, when Davey O'Brien won the school's only Heisman Trophy. O'Brien started all of those games, the longest winning streak by a quarterback.
No. 1 Ohio State and No. 4 West Virginia both have won 11 games in a row, now the best in I-A. The NCAA's longest streak is the 17 in a row by Division II Grand Valley State.
Beck threw for a MWC-record 517 yards and five touchdowns last season against TCU, which allowed only nine TDs passes in its other 11 games. The Frogs had allowed only one passing TD in its first three games this season, and held pass-happy Texas Tech to only a field goal in its last game Sept. 16.
On BYU's first possession after halftime, Beck converted two third downs before the 40-yarder to Reed, hitting the receiver in stride inside the 5 on a third-and-10 play for a 17-3 lead.
Ballard threw a 2-yard TD pass to Brent Hecht, but TCU didn't get any closer. Beck responded with consecutive scoring passes in the fourth quarter.
After Jared McLaughlin's 21-yard field goal ended a 15-play, 75-yard drive to put BYU up 3-0, TCU got to the 10 before David Nixon's blind-side sack that led to a fumble by Ballard.
The Cougars then went 82 yards, Beck converting fourth-and-1 from the TCU 33 with a 16-yard pass to Allen just two plays before Manase Tonga's 8-yard TD run.
Chris Manfredini kicked a 36-yard field goal just before halftime to make it 10-3. He missed for the first time in 20 career attempts for TCU when he was well short on a 39-yarder earlier in the second quarter.