CORVALLIS, Ore. -- Jordan Poyer and the Oregon State defense drove the No. 14 Beavers to their first 4-0 start since 2002.
Poyer intercepted three passes, the last with 3:18 left in the game, and Oregon State held Washington State to 20 rushing yards in a 19-6 victory Saturday.
A Reser Stadium-record crowd of 46,579 turned out to see a team that has gained national attention after victories over three teams that have been ranked in the Top 25 -- Wisconsin, UCLA and Arizona.
The fans did not get the offensive fireworks they may have hoped for, but they saw the Oregon State defense hold the Cougars to a pair of field goals.
The Beavers (4-0, 3-0 Pac-12) used a 12-play, 86-yard drive in the fourth quarter to finally put away Washington State. Fullback Tyler Anderson scored on a 1-yard dive after a Sean Mannion screen pass to Markus Wheaton set up the final touchdown with 4:27 left, making it 19-6.
Washington State quarterback Jeff Tuel was picked off by Poyer with 3:18 to go, and the senior defensive back ran the ball deep into Cougars territory.
The game was marred by turnovers and penalties. There were seven interceptions, including a total of four by Oregon State against Cougars quarterbacks Connor Halliday and Tuel.
Mannion also threw three interceptions, including one to 305-pound defensive lineman Ioane Gauta.
Oregon State squandered several first-half scoring chances and went into halftime holding a 6-3 lead. Washington State turned the ball over three times in the half, Oregon State twice.
The Beavers scored the game's first touchdown when Mannion connected with Wheaton in the end zone from 12 yards out with 9:17 to go in the third quarter. That capped a 10-play, 75-yard drive.
Oregon State's receiving duo of Brandin Cooks and Wheaton, who both average 134 yards receiving per game, both fell short of that but still had productive games. Wheaton caught nine balls for 95 yards, and Cooks caught five for 82 yards.
Washington State (2-4, 0-3 Pac-12) started Halliday at quarterback, but after he was picked off three times, Tuel played almost the entire second half. Halliday finished 9-for-20 with 81 yards, and Tuel was 11-for-17 for 126 yards.
Mannion, despite being sacked three times and throwing three interceptions, finished 25-for-42 for 270 yards.
NOTES: The Oregon State-Washington State series is a Northwest rivalry that dates to 1903. The Cougars have a slim lead at 48-46-3. ... The Beavers have allowed only one touchdown in two home games this season. ... Oregon State held a decisive advantage in time of possession, 39:15 to 20:45.