Oklahoma pulled off the biggest upset of the college football season so far on Saturday.

Tate Sandell kicked a 47-yard field goal on the final play to give the Sooners a 27-24 win over No. 1 Texas in the Red River rivalry game in Dallas, the Associated Press reported via ABC News.

Oklahoma won despite a struggling offense. The Sooners scored touchdowns on special teams and on defense. Their offense went three-and-out seven times, the AP reported.

Quarterback John Mateer completed passes of 13 and 20 yards on the game-winning drive, the AP reported.

Texas quarterback Arch Manning threw three touchdown passes. But both of his interceptions were costly. Texas had two late chances to take control. Gianni Spetic missed a 53-yard field goal wide right with 1:55 left. Then Manning's last pass was intercepted, setting up Oklahoma's final drive.

The Sooners are now 3-2 overall and 1-1 in the Southeastern Conference. It was their first win over a top-ranked team since they beat Missouri 38-17 in 2007. They had been 0-4-1 against No. 1 Texas teams.

Texas fell to 4-1 and 1-1 in the SEC. Longhorns fans had hoped this would be a title season. The loss will knock the Longhorns from the top spot in the rankings.

The Red River game is one of college football's oldest rivalries. It is played each year at the Cotton Bowl during the State Fair of Texas, with the stadium split between the two fan bases.

What we know: Sandell's 47-yard field goal on the final play won it 27-24.
What we don't: how far Texas will fall in the rankings.