PULLMAN — The number the Cougars fixated on this week in the lead up to their Pac-12 opener at home against Oregon was “zero.”

As in “0-0.” After starting the season a disappointing 1-2, Washington State regrouped over the bye week. The beginning of their Pac-12 slate marked a new beginning, the players said this week in the lead-up to their big tilt against the Ducks. That’s exactly what they set out to prove in front of a sold-out crowd at Martin Stadium Saturday night.

The Cougars rode a six-touchdown, 280-yard performance from their three running backs to beat Oregon 51-33 and notch their first back-to-back wins against the Ducks since the 2002 and 2003 seasons.

It also marked the first time since the 2011 season that WSU (2-2) has scored 50 points in two consecutive games.

“We’ve got a lot of work to do, but we’re taking this Pac-12 play as a new season,” WSU quarterback Luke Falk said. “Right now, we’re 1-0, there were a lot of positives, and I think we’re gonna learn from it.”

For once, the aerial fireworks usually associated with WSU’s Air Raid offense played a supporting role as the Cougars’ running-back trio of Jamal Morrow, Gerard Wicks and James Williams ran away with the show.

The triumvirate’s six rushing touchdowns were the most the Cougars have scored in one game since 1996, when they reeled off six rushing scores against Louisiana-Monroe. More impressively, for the second game in a row, WSU’s impressive backs reset the record for single-game rushing yards in the Leach era.

“The (offensive) line did a great job tonight, all the credit goes to them,” Morrow said. “I don’t think anybody expected six touchdowns out of us. It’s great. Just to come out here and have a great performance like that, we can only build on that, learn from our mistakes and keep going.”

Wicks got things going on the ground, starting the second quarter with a 4-yard rushing score, and ending the quarter with a 2-yard touchdown run that put the Cougars up 28-14 going into the locker room. He had 11 carries for 60 yards.

Then, Morrow got in on the action. The junior game captain had 13 rushes for 122 yards, scoring on a 10-yard run midway through the second quarter, and then again on a 14-yard scamper in the fourth.

Williams reserved his best moves for the second half, recording 76 of his 91 yards after halftime. Thirty-eight of those second-half yards came on the first of his two touchdown runs in the fourth quarter, and he punctuated that with a 3-yard score to give the Cougars a commanding 51-26 lead with 2:54 remaining in the game.

“It’s like a chain reaction,” Wicks said. “I started it off, then Jamal came on. We all excite each other. When I score and we all run out together, we all celebrate together, it’s like a brotherhood, we all gotta bring something to the table, and us playing well tonight gave us the advantage to win the game.”

Unlike the nail-biter of a win the Cougars eked out in double overtime in Eugene last season, they left nothing up to chance this year, scoring three unanswered touchdowns in the second quarter to go up 28-14 in a game in the Ducks never led.

“I thought the whole game we had good energy and were highly motivated,” Leach said. “We did a better job running our feet on contact and did a better job seizing plays. We weren’t waiting for somebody else to do something.”

For the first time all year, Washington State looked sharp from its opening drive. Gone were the penalties, missed tackles and missed throws that seemed to plague the Cougars early on through their first three games.

The miscues were replaced by a ferocious defense that bottled up Oregon running back Royce Freeman and kept quarterback Dakota Prukop running from the pass rush all evening long to finish with a season-high eight tackles for loss.

On the other side of the ball, the Cougars opened with a coolly efficient offense that stretched the field and scored on its first possession, when quarterback Luke Falk connected with Gabe Marks on a 7-yard touchdown pass.

Falk started the night deadly accurate, opening 10 of 10 for 86 yards and the TD pass to Marks. He finished 36 of 48 for 371 yards.

Oregon’s Freeman finished with 138 yards rushing on 19 carries and three touchdowns. He scored both of Oregon’s first-half TDs, busting out an 11-yard run in the first quarter, then barreling into the end zone on a 1-yard score in the second quarter to at least help the Ducks keep pace with WSU and tie the score at 14-14 with 9:22 remaining in the half.

Falk and Co. faltered a little after halftime, going 0 for 2 in the red zone on consecutive drives to keep things interesting in the third quarter.

But the Cougars’ defense more than made up for the offense’s third-quarter red-zone issues, forcing turnovers on back-to-back drives to keep WSU comfortably ahead.