Tuesday marks the 25th anniversary of an indelible moment in college football history -- the Fifth Down Game between Colorado and Missouri.

On their way to a share of the national championship, the visiting Buffaloes benefited from an infamous officiating mistake and beat the Tigers 33-31 at Memorial Stadium in Columbia, Missouri, on Oct. 6, 1990. Colorado, ranked No. 12 in the nation at the time, was awarded five downs on the game's final series and scored the winning touchdown as time expired.

The Buffs actually dropped two spots in the AP poll after the win but won their next seven games to finish 11-1-1. The Tigers were coming off an impressive victory over a ranked Arizona State team and might have been able to use a win over Colorado as a springboard. Instead, their season unraveled on the way to a 4-7 record.

Here are the five things you should know about the Fifth Down Game:

1. Fifth down might not have been the only mistake

The extra play isn't the sole reason Missouri players and coaches had to question the outcome.

Officials momentarily stopped the game clock with seven seconds remaining as players climbed off Buffaloes running back Eric Bieniemy. The Tigers believed there was no evidence of their players stalling as the pile was sorted out and thought the stoppage was unfounded.

More damning might be the fact that some replays and photographs appeared to show Colorado quarterback Charles Johnson down short of the goal line on the final play.

You can watch the entire final drive here. The last series starts at the three-minute mark and fifth down is at the 7:05 mark.

2. The scene almost got really ugly afterward

Some fans chased the game officials into an equipment room behind the south end zone as others tore down the nearby goalpost.

Security guards were needed to protect the sequestered officials from a potential onslaught as the situation escalated quickly. Bottles and rocks were flying as fans swarmed the field, bumps and bruises were suffered and a few arrests were made. Fortunately, that's as bad as things got before order was restored.

Unrelated to the postgame mayhem -- but possibly related to the tension of the fourth quarter -- a spectator suffered a heart attack during the final series. The fan was brought down to the running track behind the Colorado bench to receive medical attention. Attempts to revive him failed, and he ultimately died.

3. About that goalpost ...

Tigers fans also had brought down the goalpost at the south end zone the previous week. Further, the goalpost at the north end zone was vandalized hours after the loss to Colorado.

"It's bent really bad," Missouri assistant athletic director Joe Castiglione told the St. Louis Post-Dispatch. "We don't know for sure if we can fix it."

This was problematic, considering the school's spare goalpost already had replaced the one damaged after the win over Arizona State. Presumably, the problem was sorted out before the Tigers played host to Kansas State two weeks after the Colorado game.

4. Colorado coach Bill McCartney played at Missouri

McCartney was a three-time letterman for the Tigers. He played in the 1960 and '61 Orange Bowls and was named to the All-Big 8 second team as a senior. He later served as an assistant to Bo Schembechler at Michigan before taking over at Colorado in 1982.

Other figures of note from the Fifth Down Game:

• Future Vanderbilt, LSU and Indiana head coach Gerry DiNardo was Colorado's offensive coordinator. Future Northwestern and Colorado head coach Gary Barnett -- another Missouri alum -- was the Buffaloes' quarterbacks coach.

• Colorado linebacker Chad Brown went on to play 15 NFL seasons with the Pittsburgh Steelers, Seattle Seahawks and New England Patriots, and punter Tom Rouen went on to play 13 NFL seasons. Other Buffaloes from that game who reached the NFL include All-American running back Eric Bieniemy, center Jay Leeuwenburg, wide receiver Mike Pritchard and linebacker Alfred Williams -- all of whom played nine NFL seasons. Bieniemy rushed for 217 yards on 29 carries in the Fifth Down Game and placed third in Heisman Trophy voting that season behind BYU's Ty Detmer and Notre Dame's Raghib Ismail.

• Future Boise State and Arizona State head coach Dirk Koetter, currently the Tampa Bay Buccaneers' offensive coordinator, was the Missouri offensive coordinator. Future Philadelphia Eagles and Kansas City Chiefs head coach Andy Reid was Missouri's offensive line coach.

5. The man operating the down marker was a Missouri alum

Rich Montgomery is a Missouri alum and lifelong Tigers fan. One of his sons was a walk-on at Mizzou who later became a grad assistant with the program.

He's also the unlucky guy who happened to be in charge of the down marker for the Fifth Down Game, having worked on the chain crew at Memorial Stadium for two decades. Upon hearing the final series recounted over the radio on his drive home from the game, he literally pulled over and threw up.

Montgomery works as a member of the chain crew at Missouri to this day -- his 45th season in that role.

Seemingly, time has erased some of the disappointment on the Missouri campus, where the Tigers athletics website humorously references the gaffe when visitors arrive at a dead link.

You can read more about the Fifth Down Game in this Outside The Lines story from 2010.