CORVALLIS, Oregon (AP) — While Oregon State coach Mike Riley was angry at halftime that his team was struggling against Portland State, his defense was seething.
The Beavers were down 14-13 going into the break against the Vikings, facing the prospect of dropping their opener to a lower division team for the third time in four seasons.
Instead, the Beavers took out their anger in the second half, forcing turnovers on five of Portland State's first six possession of the second half to help carry the Beavers to a 29-14 come-from-behind victory over the Vikings.
Oregon State quarterback Sean Mannion passed for 328 yards and one touchdown and rushed for another score, and Garrett Owens added five field goals. But the key was a Beavers' defense that held Portland State to 40 yards total offense in the second half.
"Defensively, the second half we couldn't have done much better," Riley said. "We played smart, took away what they were doing against us, and, really, they tried a million different double moves and ... we were sound. That was nice to see."
"Offensively, it was really sporadic. We'd make a few plays and then not look too good. It just didn't feel good at all."
Oregon State scored on six of nine trips inside the red zone, but came away a bit miffed considering the scores were a 6-yard touchdown run by Mannion and five field goals by Owens of 25, 25, 31, 26 and 23 yards.
"It's about the win," said Mannion, who completed 26 of 45 passes. "Our defense played outstanding and gave us a lot of extra possessions, and we've got to be able to capitalize when they do that, especially when we have a short field.
"As the game went on, we kind of gained momentum. We really got into a rhythm and kind of had everything going for us. Certainly, it was far from perfect, but the win is what matters."
Portland State backup quarterback Paris Penn was a force in the first half when he had five carries for 102 yards and scored on runs of 58 and 11 yards. The second touchdown came with 5:38 to play in the half and gave the Vikings a 14-13 lead.
In the second half, the Beavers held Penn to 10 yards on four carries. They also intercepted one pass by Portland starting quarterback Kieran McDonagh, intercepted another pass from wide receiver Darnell Adams, and pounced on three Vikings' fumbles.
"The first half, I'd like to think it was a little bit of the first-game jitters," Beavers defensive end Dylan Wynn said. "As you can see, our defense really started to get in the right direction of where we should be when it comes to how we'd like to execute stuff."
Trailing 6-0, Portland State crossed midfield for the first time on the first play of the second quarter when Penn scored on a 58-yard run to put the Vikings in front 7-6.
The Beavers answered with a 10-play, 82-yard scoring drive with Mannion scoring on a 6-yard run to make it 13-7 with 9:36 to play in the second quarter. It was Mannion's second career rushing touchdown and first since his freshman season.
Penn put the Vikings back in front 14-13 with 5:38 remaining the half when he scored on an 11-yard run, capping a nine-play, 73-yard scoring drive that was aided by four OSU penalties, including a late hit out of bounds and a roughing the passer call.
At halftime, Oregon State had run 37 plays to Portland State's 27 and had a 285-175 advantage in total offense. The Beavers also had been penalized 10 times for 89 yards, while the Vikings were flagged once for 10 yards.
"It all looked bad, and it had a really bad feeling for what our team was about there for a while," Riley said. "That's one of the redeeming things about the game, in particular, was how defensively we responded in the second half, because it was a lot of bad looking stuff.
"It still wasn't very pretty in the second half, but I think we went out with good intentions. They were pretty mad. I was pretty mad when I came in, and then they got madder, so I thought that was pretty good."
Portland State opened the second half with a turnover when wide receiver Darnell Adams attempted a deep pass that was intercepted by Oregon State's Tyrequek Zimmerman at the Beavers' 40.
OSU then went 51 yards in eight plays, setting up a 26-yard field goal by Owens that put the Beavers back on top, 16-14.
The Beavers forced three more turnovers before the end of the third quarter, including a fumble that set up Mannion's 23-yard touchdown pass to Woods, and an interception that set up a 31-yard field goal by Owens.
"We just hit the self-destruct button one too many times," Portland State coach Nigel Burton said. "Obviously, the turnovers were the things that changed the game. But we were resilient, and I think it is still something we can build off of even though there is no such thing as moral victories."
Oregon State had 505 yards total offense, while holding Portland State to 215 yards.
"Defensively, it was kind of hodgepodge early on," Burton said. "We didn't have our headsets the entire game, so we were guessing personnel and it was real interesting. Our coaches, I think, set the tone early, because they didn't freak out.
"I probably was the worst, because I couldn't talk to anybody. But because our coaches didn't freak out, our players didn't freak out, and they kept playing and that's why we were up at half."
Oregon State had stumbled twice against FCS teams in recent home openers, losing 29-28 to Sacramento State in 2011 and 49-46 to Eastern Washington last season.
Portland State fell to 2-31 against NCAA Division I FBS programs, including a 0-13 mark against Pac-12 teams and a 0-4 record against Oregon State.
Next week, the Beavers play at Hawaii, while the Vikings are home against NCAA Division II Eastern Oregon.