Tinkle and Kelley, who were honored in a pregame ceremony at Gill Coliseum, combined for 43 points in the Beavers 74-56 victory over California.
Tinkle scored a game-high 24 points and received a big hug from his dad, OSU coach Wayne Tinkle, after leaving the game for the last time with 51 seconds left.
Kelley had a Pac-12 career high 19 points, along with eight rebounds and three blocks.
"Proud of these two guys for what they stand for number one," Wayne Tinkle said of his seniors. "All that they've done, who they are and the way they led us (today). What a way to go out."
The Beavers (17-13, 7-11 Pac-12) take a two-game winning streak into next week's Pac-12 tournament in Las Vegas.
Tinkle became Oregon State's career-leading scorer in Thursday's 68-65 win against Stanford, and finished the regular season with another strong performance.
"At the beginning I thought I was gonna be worse than I was," Tres Tinkle said of his pregame emotions. "I'm very competitive and at the end of the day we're trying to win, so it was pretty easy to just kind of get back into what's important, what to focus on, and try to get a win and it'll make it more fun after the game."
Bradley, who scored 23 points in the Bears' 69-67 home win over Oregon State on Feb. 1, finished with eight points on 2 of 10 from the field. He picked up his fourth foul with 12:05 remaining and Oregon State leading by 10 points.
"Matt's had a great year for us and I just felt like today, he looked a little worn down and let's give Oregon State's defense credit for some of that," California coach Mark Fox said. "The foul trouble was an issue and it wasn't obviously one of his better days."
Oregon State played primarily a zone defense and it was effective. The Bears connected on just 37% percent of their field goal attempts and were 4 of 17 behind the arc.
The Beavers shot 44.4% and were 9 of 22 on 3-pointers.
Oregon State took its biggest lead at 60-42 on Kelley's jumper with 5:51 remaining.
The Bears responded with a 9-0 run to cut the lead to nine points, but they would not get closer.
"It was a great game," said Kelley, who is second in the nation in blocked shots. "I think our guys really locked in since the start of the game."
Oregon State led 26-21 at the break behind Tinkle's 11 points.
Bradley didn't get in the scoring column until he connected on a 3-pointer with less than three minutes remaining in the first half.
California: Bradley is the only player averaging in double figures this season. . The Bears are 1-10 in road games.
Oregon State:. . Tinkle extended his school record for consecutive double-figure scoring games to 95. . The Beavers likely need to win the Pac-12 tournament to advance to March Madness for the first time since 2016.
Both teams play Wednesday in the first round of the Pac-12 tournament at T-Mobile Area in Las Vegas with opponents to be determined.
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