It's quite rare for a major-conference team to serve as a legitimate Cinderella story of the men's NCAA tournament, but that glass slipper fits beautifully on the Elite Eight-bound and No. 12 seeded Oregon State Beavers.

Prior to last Friday, Oregon State's most recent win in the NCAA tournament came in 1982. But the tournament accomplishments of the "Orange Express" from 1980-82 were later vacated due to impermissible benefits, meaning the program's most recent official tournament victory came in 1975.

That means—as far as the NCAA record books are concerned—both DePaul and Rutgers had been to a Final Four more recently than Oregon State won a tournament game.

Not only is this a Cinderella story by ancient history standards, but even the much more recent history suggests there was no way to see this coming.

Just five weeks ago, the idea of Oregon State making it into the NCAA tournament was borderline incomprehensible.

The Beavers were 11-11 overall with woeful home losses to Wyoming and Portland on their resume. (Portland did not win another road game this season, nor did it win another game against a KenPom Top 200 opponent.)

The only time we even tangentially mentioned Oregon State in bracketology conversations was if we were either pointing out USC's worst loss of the season or mentioning how bad short-handed Oregon looked against the Beavers in its first game back from a COVID-19 pause.

In the quarterfinals of the Pac-12 tournament, Oregon State trailed UCLA 32-16 in the first half, was down by four with less than two minutes to go and was only able to get that game into overtime when Jules Bernard missed what likely would have been a game-winning free throw for the Bruins.

In the Pac-12 championship against Colorado, one of the best free-throw shooting teams in NCAA history went just 12-of-20 from the charity stripe and still had a chance to win it at the buzzer, but McKinley Wright IV's half-court heave was nowhere close to finding its mark.

Even after winning the Pac-12 tournament, Oregon State ended the year ranked 91st in the NCAA Evaluation Tool rankings and 85th on KenPom.

There has been a lot of chatter in the past week about certain teams (most notably Loyola-Chicago) being under-seeded by the selection committee, but Oregon State's No. 12 seed was much deserved. There's no way the Beavers would have gotten in without that automatic bid.

After beating those long odds just to get into this dance, they keep refusing to go home.

Their tourney journey began with a 14-point win over Tennessee in which their lethal Pac-12 tournament three-point stroke (43.9 percent) found its way to Bankers Life Fieldhouse. Jarod Lucas and Zach Reichle led the Beavers through a 10-of-21 night from distance.

After knocking out a Volunteers squad with two potential lottery picks (Keon Johnson and Jaden Springer), Oregon State proceeded to get a super physical win over Cade Cunningham and Oklahoma State. That OSU-OSU showdown featured 73 combined free-throw attempts, and the Beavers made 91.4 percent of their freebies.

Those free throws were once again critical in the process of beating Cameron Krutwig, Sister Jean Dolores-Schmidt and the Loyola-Chicago Ramblers in the Sweet 16. That game was a rock fight of the highest order, but the Beavers went 18-of-20 from the charity stripe—most of those in the final three minutes to keep the Ramblers from having any chance of mounting a comeback.

After shooting 15-of-16 from the free-throw line against Oklahoma State, Ethan Thompson sank all eight of his tries against Loyola-Chicago. Oregon State's senior leader has averaged 20.3 points, 7.0 rebounds and 3.3 assists through the first three rounds.

But the biggest reason for Oregon State's success has been its defense, which is pure madness if you watched this team try to play defense during the regular season.

In 17 of 29 games played prior to the tournament, Oregon State allowed at least 1.0 points per possession (PPP). In a mid-January loss to Arizona, that rate was 1.38 PPP. In the home loss to Oregon in OSU's regular-season finale, the Ducks scored 1.33 PPP.

The Beavers had, arguably, the ninth-best defense in the Pac-12.

In each of their three NCAA tournament games, though, the Beavers defense has clocked in below 1.0 PPP allowed. All told, it's 184 points on 205 possessions (0.89 PPP), and it's mostly a product of intentionally mucking things up in the paint against mediocre three-point shooting teams.

With big man John Fulkerson unavailable for Tennessee because of a facial fracture suffered in the SEC tournament, Oregon State basically begged Tennessee to settle for long jump shots, and the inconsistent Volunteers obliged that request. Same goes for the game against Oklahoma State, and those first two opponents shot a combined 13-of-53 (24.5 percent) from three-point range.

Against Loyola-Chicago, Wayne Tinkle unleashed a zone defense designed to A) keep Krutwig in check, B) eliminate the backdoor cuts that the Ramblers used to destroy Illinois and C) force them to settle for threes instead of their preferred two-point buckets. It worked to perfection. The Ramblers shot just 1-of-13 from distance in the first 30 minutes, and it was too little too late when those shots finally started falling.

Loyola-Chicago had not faced much zone defense during the regular season, and it took the Ramblers a long time to figure out how to navigate it. They ended up scoring 58, but they were held to 24 for the first 28 minutes.

Because of that savvy decision by Tinkle, the Beavers are improbably on their way to the Elite Eight. They join 2002 Missouri as only the second team in NCAA tournament history to reach a regional final as a No. 12 seed or worse.

Why stop there?

Oregon State could certainly win Monday's game against Houston. Like both of the Midwest Region's Sweet 16 matchups, it's probably going to be a "race" to 60 points. If the Beavers can keep the Cougars from dominating on the offensive glass, they could keep this wild ride going for one more weekend.

Because of Oregon State's conference affiliation, most will refuse to view this run as unlikely as the Final Four runs of No. 11 seeds George Mason (2006), VCU (2011) and Loyola-Chicago (2018). Nevertheless, the Beavers are one win away from the unlikeliest Final Four appearance of all-time.

If they get it done, I'm confident I speak for everyone in hoping that the 6'10" Tinkle dons a pair of very large glass slippers to coach that national semifinal game against the winner of Arkansas vs. Baylor.

Kerry Miller covers men's college basketball and college football for Bleacher Report. You can follow him on Twitter, @kerrancejames.