They started showing up over six hours before the doors opened.

The lines and the storm clouds grew, but the buzz outside of the sold-out venue would not be dampened.

The masses weren’t huddled in the rain awaiting the unveiling of a new iPhone or a local Fyre Festival or a football Civil War.

A capacity crowd of 12,364 showed up to watch two of the nation’s best women’s basketball programs, which happen to both be located in the same state, play Friday night at Matthew Knight Arena.

No. 3 Oregon stole the spotlight on its home stage with a 77-68 victory over No. 9 Oregon State.

The two rivals will complete the regular-season series Monday in front of another packed house at Gill Coliseum.

“To see what has happened is incredible,” said Oregon coach Kelly Graves, who noted that seniors Maite Cazorla and Oti Gildon played in front of 956 people during their first home game three seasons ago. “The people that were here were here to see a basketball game. We didn’t give any tickets away. We didn’t have any promotion where you buy a cup of coffee and get a ticket.

“These people wanted to be here, and that’s pretty cool.”

Sabrina Ionescu finished with 29 points, nine assists and five rebounds to lead the Ducks (24-1, 13-0) to their 17th consecutive victory, the nation’s longest active winning streak.

The Beavers (20-5, 10-3) are now three games behind Oregon in the Pac-12 regular-season race with five games remaining.

“We treated it like another game,” Ionescu said. “We didn’t do anything differently, we didn’t prepare differently. We scouted them just like we would any other team.

“But it’s definitely a little bit sweeter to get that win against a team that is right from down the street from us and then be able to go down there Monday and hopefully get a win as well.”

Destiny Slocum, who led her team with 19 points, started to heat up in crunch time. When the Maryland transfer hit her fourth field goal of the fourth quarter, Oregon State had cut a 10-point deficit to 64-60.

But the Ducks defended the 3-point arc and the post at an elite level in the second half.

“She made some tough shots, let’s face it. Shots with a hand in her face,” Graves said of Slocum, who finished 6-for-15 from the field. “She got more aggressive, but I think to the detriment of some of the rest of them.”

Ionescu and Ruthy Hebard executed a pair of perfect pick-and-roll plays and Satou Sabally splashed her fifth 3-pointer of the game to put Oregon back in control with a 71-60 lead with 3:07 remaining.

The Beavers scored the next six points before Ionescu put the game away with back-to-back jumpers.

“I mean, I’m still kind of bummed,” Ionescu said after making 12 of her 24 shots. “I didn’t shoot the ball very well. I left a lot of points on the board and I think I should have been able to hit some of those shots. But games like that, that’s what’s going to happen. They’re so long and the game is just going up and down, adrenaline is pumping.

“Credit to my teammates. They made shots when they had to. Ruthy made layups when she had to.”

Hebard had 21 points and 11 rebounds, and Sabally added 18 points.The only other Ducks to score were Erin Boley (five points), Cazorla (two) and Gildon (two).

“I loved our effort,” Oregon State coach Scott Rueck said. “Knowing what this environment was going to be like tonight in a rivalry game, I thought we were composed and I thought we played great basketball. There were a lot of positives to take away. Oregon is such a good team, and they made us pay for every mistake.

“Now for Monday, we have to be better.”

Oregon turned up the defensive intensity in the third quarter, forcing two shot-clock violations by the Beavers while building a 49-40 lead after a high-arching 3-pointer by Ionescu.

The reigning Pac-12 player of the year added a bank shot and another 3-pointer to extend the cushion to 56-46 at the end of the third quarter.

“We were always on our toes,” Ionescu said. “We didn’t know what they were going to run. They were coming at us with a new play every single possession. So we just had to be locked in and understand the personnel, understand what we wanted to do, and take care of it and get stops when we had to. I think we did that down the stretch.”

The Ducks led 39-35 at the intermission after shooting 50 percent (5-for-10) on 3-pointers.

Oregon grabbed an early 7-2 lead before the visitors settled in to the hostile road environment.

Katie McWilliams hit a 3-pointer as the shot clock was expiring and Joanna Grymek scored three times from point-blank to tie the score 11-11 at the first media timeout.

“We saw that we were kind of struggling at first (defending Grymek),” Hebard said. “I think I just needed a little more help, and my teammates gave me that down the stretch.”

After McWilliams gave the Beavers their first lead, Sabally answered with a 3-pointer to start the Ducks’ 7-0 run to end the first quarter with an 18-13 lead.

Hebard grabbed an offensive rebound and scored to give Oregon a seven-point lead (25-18) in the second quarter.

Taya Corosdale hit a 3-pointer and Mikayla Pivec muscled her way for a tough basket in the paint to give Oregon State a 30-27 advantage.

Sabally capped a 10-0 run with a 3-pointer from the corner to give the Ducks a 37-30 lead, which they never relinquished again.

Now the Civil War scene shifts to Corvallis.

“Big Monday is going to be just as loud up there,” Graves said. “I don’t think they have as many people in their arena, but it will be just as loud. A lot blacker and oranger.”