For the first time, it's Mississippi State.
Hunter Renfroe hit a three-run homer off the back wall of the left-field bullpen, and Kendall Graveman and two relievers held the Beavers in check in a 4-1 victory on Friday.
"I know it sounds crazy, but our kids just think something good is going to happen and, by the way, our coaches do, too," Bulldogs coach John Cohen said. "I think these guys are on a little bit of a roll for sure."
The Bulldogs (51-18) beat the Beavers (52-13) for the second time in the CWS and get two days off before starting the best-of-three championship round against North Carolina or UCLA.
Renfroe's homer came on an afternoon the wind was blowing in at a ballpark that surrenders few home runs. He had already seen teammate Wes Rea come up short with a fly to the left-center power alley that Michael Conforto caught against the wall on perhaps the best defensive play of the CWS.
Renfroe's 16th homer of the season, and first since May 4, came on a 3-1 pitch from Andrew Moore (14-2) and put the Bulldogs up 4-0 in the fifth. It was only the third homer in 11 CWS games, and there was no doubt it was out, even though Renfroe didn't initially see it that way.
"I was running hard out of the batter's box and going for a double," he said. "I kind of hit it off the end of the bat, but I was able to get enough backspin on it."
Oregon State (52-13) went 2-2 in its first CWS appearance since winning back-to-back national titles in 2006-07.
"It's very difficult when eight teams show up at Omaha, and seven of them lose their last game and feel like they had a poor season," Beavers coach Pat Casey said. "We're not hanging our head at all. Our guys are obviously disappointed, and I think they're more disappointed in the fact that they won't get a chance to play together as a team again."
Graveman (7-5) worked the first 5 2-3 innings, allowing one run and four hits. Ross Mitchell and Jonathan Holder finished, with Holder getting the last two outs for his 21st save of the season and school-record 30th of his career.
The eighth-round draft pick of the Toronto Blue Jays, Graveman also started the first game against the Beavers. He allowed four runs in 4 2-3 innings that day and was let off the hook when Rea doubled in the winning runs in the eighth.
"For me to see them the other day was pretty big on my part," Graveman said. "Once I see a team physically, not just on video, I feel like I can discover a few more things that I can go to. I didn't want to do the same thing I did the first outing because I thought they barreled up a few more balls than they did today."
The Bulldogs built on a 1-0 lead after Moore retired their first two batters in the fifth. Adam Frazier and Alex Detz singled before Renfroe, the No. 13 overall pick by San Diego in the recent draft, turned on Moore's breaking ball.
Moore gave up four runs on nine hits in 4 2-3 innings, his shortest outing of the season. Jace Fry pitched 3 1-3 innings of two-hit shutout relief, but the Beavers' offense couldn't crack Mitchell and Holder.
Mississippi State had beaten the Beavers 5-4 in the CWS opener, with Danny Hayes' deep fly to right dying on the warning track in the bottom of the ninth inning.
There was no such drama this time.
Conforto made the play of the day to rob Rea of extra bases when he retreated to the warning track, jumped to make the catch and held on as he slammed against the wall.
Beavers shortstop Tyler Smith was so impressed that he went out to left to give Conforto a hug. Conforto later threw out Rea at the plate after catching a ball in foul territory.
Casey said the play on Rea brought energy to the dugout.
"We've been talking all yearlong about how good a defender he is," Casey said. "It gets overlooked, but he gets great jumps on the ball. It was an inspiration to our club."