TEMPE, Ariz. — Marion Grice ran for 118 yards and two touchdowns, Robert Nelson returned his second interception 23 yards for a touchdown in the fourth quarter, and No. 21 Arizona State overcome a second half lull to beat Oregon State 30-17 Saturday night.
Arizona State (8-2, 6-1 Pac-12) dominated the first half to take a 20-0 lead before stumbling through the third quarter. The Sun Devils halted Oregon State's momentum with a blocked field goal in the fourth quarter and put it out of reach when Nelson raced in on Sean Mannion's fourth interception of the game.
Arizona State has won five straight and 19 of 20 at home against Oregon State (6-4, 4-3), which has lost three straight overall.
Mannion threw for 320 yards and two touchdowns, but has seven of his 10 interceptions this season in the past two games.
Grice scored on a pair of 1-yard runs to become the third Arizona State player to score 20 touchdowns in a season, joining Terry Battle, who had 20 in 1996, and Wilford White, with 22 in 1950.
Arizona State needed this game to preserve its lead in the Pac-12 South before next week's showdown with No. 13 UCLA, which is on the Sun Devils' heels in the division.
Oregon State needed it get back on track after following a six-game winning streak with losses to Stanford and USC.
The Sun Devils dominated at the start.
On offense, they raced 75 yards on their opening drive for a touchdown run by Grice, his first in three games. Jaelen Strong had 66 yards receiving on the drive, 16 more than the previous three games combined.
Arizona State was derailed briefly when Taylor Kelly threw interceptions on the next two drives — one due to pressure, another on an underthrow — but kept rolling after that.
D.J. Foster put scored on an 8-yard run — the extra point was blocked — and Grice followed a muffed punt by Brandin Cooks with another TD run to make it 20-0.
Arizona State's defense was even better, dominating the nation's 25th-best offense for most of the first half.
The Sun Devils held Oregon State to 38 total yards in the first quarter and intercepted Mannion twice in the half. Oregon State finally got a sustained drive going in the closing minutes, but had to settle for Trevor Romaine's 22-yard field goal at the horn after Arizona State's Alden Darby tackled Micah Hatfield at the 5-yard line with a second left.
The momentum started to shift in the second half — well, after Darby made a diving interception of Mannion on Oregon State's opening drive.
Mannion followed his third pick by picking apart the Sun Devils on a 96-yard scoring drive to cut the lead to 20-10. Caleb Smith capped with a 6-yard catch-and-run over the middle.
The Beavers were much better on defense, too, holding Arizona State to 34 yards and two first downs.
Oregon State still had momentum on its side to start the fourth quarter, but center Isaac Seumalo was called for an unnecessary roughness penalty to back the Beavers up. Arizona State's then Davon Coleman got a hand up to block Romaine's 48-yard field goal attempt.
Arizona State got back to its quick-striking ways on the ensuing drive, going up 23-10 on Zane Gonzalez's 18-yard field goal, and Nelson sealed it with his first career pick-six.