Arizona coach Chip Hale celebrates with his Wildcats after their 4-3 walk-off victory to clinch the Pac-12 regular-season championship against Oregon State at Hi Corbett Field on May 18.

 Kelly Presnell, Arizona Daily Star

The final regular-season championship in the Pac-12 Conference as we know it came down to the final inning of the final league contest.

The last champ in the Conference of Champions? Chip Hale’s Arizona Wildcats.

Brendan Summerhill’s two-RBI double in the bottom of the ninth inning gave Arizona a 4-3 walk-off victory over Oregon State in front of an announced crowd of 4,949 at Hi Corbett Field.

After No. 6 OSU won the first two games of the series in dominant fashion, the Pac-12 regular-season crown boiled down to Saturday night’s game. Had they lost, the 14th-ranked Wildcats would have dropped to third place in the conference. Instead, they’ll be the No. 1 seed in the Pac-12 Tournament next week, facing No. 9 seed Washington at 7 p.m. Wednesday at Scottsdale Stadium.

It was Arizona’s seventh walk-off victory of the season.

“It's just fitting to end it like that,” said UA starter Cam Walty, who limited the powerful OSU offense to three runs in 8⅓ innings. “What better way ... to win it.”

The Arizona Wildcats dogpile in center field after a walk-off, come-from-behind 4-3 win against Oregon State at Hi Corbett Field to take the last-ever Pac-12 regular-season championship on May 18.

The Wildcats’ postgame celebration was worthy of their accomplishment. First, they swarmed Summerhill, who rocked a 2-1 slider to the track in right-center to score Tommy Splaine and Maddox Mihalakis. With “We are the Champions” blaring, they donned black Pac-12 Champion T-shirts with matching white hats and sung the UA fight song. They saluted the delirious fans in the first base stands. Finally, they dumped a bucket of Powerade onto Hale.

“I’m really proud of them obviously,” said Hale, whose team was picked to finish ninth in the preseason Pac-12 coaches poll. “There was so much fight in that dugout the whole game. And why not be a walk-off? We’ve been doing it all year.

“Summerhill’s been a part of a lot of them. I told (assistant coach) John DeRouin, sitting next to me, ‘He’s gonna hit one in the gap.’ And I was right for once in my life.”

After withering against the OSU onslaught in the first two games, the Wildcats (33-20, 20-10 Pac-12) came out with energy and determination. Their dugout was animated, and they took their first lead of the series in the second inning.

Arizona starter Cam Walty deals in the seventh inning against Oregon State in their Pac-12 game at Hi Corbett Field on May 18. Walty would allowed three runs in 8⅓ innings in the Wildcats' 4-3 comeback win.

Garen Caulfield, batting cleanup for the first time this season, led off with a double to right-center. Caulfield advance to third on a groundout to first, and another groundout to first brought him home.

The lead didn’t last long as OSU (41-13, 19-10) scored two runs in the top of the third.

Walty shut the Beavers down almost the rest of the way. He exited with the score 2-2 after yielding a one-out double in the top of the ninth.

OSU scored off reliever Anthony “Tonko” Susac to take a 3-2 lead, and Walty would have been charged with the loss if Arizona hadn’t rallied.

Considering that the Beavers had scored 25 runs in the first two games of the series, that would have been a most undeserved defeat.

“None of this happens without Cam Walty,” Hale said. “He kept us in the game.”

Walty allowed six hits and two earned runs. He struck out eight and did not walk a batter for the seventh time in 13 appearances.

“I've never experienced this really,” Walty, a transfer from Nevada, said as the celebration raged behind him. “There's so many people here. We knew what we had to do. Just being able to achieve that, even with all the struggles and how we started, it's amazing.”

Summerhill scored the tying run in the bottom of the sixth inning after beating out a grounder to second and coming home on Caulfield’s sacrifice fly.

Summerhill had a chance to give the Wildcats the lead the next inning with the bases loaded and one out. He instead grounded into a double play. TrackMan recorded Summerhill’s one-hop liner at 103 mph, but it went right to shortstop Elijah Hainline.

Arizona again generated traffic in the eighth, putting runners on first and second with one out. But Andrew Cain struck out, and Adonys Guzman flew out to left.

Susac walked the first batter he faced in the top of the ninth, putting runners on first and second with one out. Shortstop Mason White’s diving stop and throw to third — upheld by replay — prevented OSU from loading the bases. But No. 9 hitter Jabin Trosky singled down the first base line to score Easton Talt and give the Beavers a 3-2 lead.

Arizona’s Brendan Summerhill (4) jumps for joy after smashing a two-RBI double to center field in the bottom of the ninth to edge Oregon State 4-3 and take the regular season Pac 12 championship at Hi Corbett Field, May 18 2024, Tucson, Ariz. The walk-off was the conference’s final regular season game, in all sports.

The Wildcats had them right where they wanted them.

“We just never give up,” said Summerhill, whose game-winning hit came off the bat at 110 mph. “It's a belief. It's a belief we can do it. We know what we have. We know that we can rally together as a group and beat anyone in the country.”

Inside pitch

• The Beavers will be the No. 2 seed in the Pac-12 Tournament, which begins Tuesday. OSU’s first game is Wednesday morning vs. No. 8 seed Stanford.

• Summerhill went 3 for 5 with two doubles. Caulfield went 2 for 2 with a walk.

• Nine UA players and four student managers were honored during a Senior Night ceremony before the game. The players were RHP Clark Candiotti, Caulfield, OF Emilio Corona, RHP Kyler Heyne, RHP Trevor Long, C Blake McDonald, P Jaeden Swanberg, Walty and LHP Bradon Zastrow. After the players were introduced and took pictures, family members threw a first pitch to each player.

• Fifth-year RHP Dawson Netz is out of eligibility but did not participate in the ceremony after doing so last year.

• Corona missed his second straight game because of a hand injury suffered Thursday night. Fellow outfielder Easton Breyfogle (hamstring) also remained out.

Arizona sophomore outfielder Brendan Summerhill discusses his two-RBI, walk-off double that gave the Wildcats a 4-3 victory over Oregon State and locked up the Pac-12 regular-season championship for the UA (video by Michael Lev / Arizona Daily Star)

Trailing 3-2 in the ninth inning of their last-ever Pac-12 baseball game, the Arizona's Brendan Summerhill hit a two-run RBI double to walk-off the Wildcats not just to a win, but also the conference's 2024 regular-season championship. (Courtesy Pac-12 Networks)

Become a #ThisIsTucson member! Your contribution helps our team bring you stories that keep you connected to the community. Become a member today.

Contact sports reporter/columnist Michael Lev at mlev@tucson.com. On X(Twitter): @michaeljlev