The Lamar Hunt U.S. Open Cup returns on Tuesday, as each Round of the 32 match is set to feature a USL club, which is a first since the 2009 edition of the historic competition. This year, a collection of eight USL Championship and USL League One clubs are set to face MLS opposition in the Round of 32 as each chases a 'cupset.'

• MORE: Where to watch the USL Championship, Jägermeister Cup, and U.S. Open Cup this week

Since the Select League and the American Professional Soccer League merged to form the USISL A-League back in 1997, United Soccer League and Major League Soccer clubs have met every year since in the U.S. Open Cup - the country's oldest ongoing national soccer competition.

Across four decades and various levels of the United States' soccer pyramid, USL teams have delivered 81 cupsets to MLS opposition, winning over 25% of all contests between MLS and the USL's various leagues throughout the decades. 

Since the U.S. Open Cup resumed following the COVID-19 pandemic, clubs from the USL Championship and USL League One have registered 13 cupsets against MLS opposition, aligning with the USL's historic average of 25%. For some context, across the most prominent domestic cup competitions in Europe (England, Italy, Spain, Germany, France) since COVID-19, lower-division opponents have won an average of 18% of their contests against top-flight opposition. 

Below, we recount some of the most memorable USL-MLS cupsets over the past 27 editions of the U.S. Open Cup.

To catch the next cupset, all of this year's Round of 32 matches will be streamed at www.uslsoccer.com/watch.

1997 (Third Round): San Francisco Bay Seals 2 - 1 Kansas City Wizards

The USISL D-3 Pro League's San Francisco Bay Seals made waves in the 1997 U.S. Open Cup, orchestrating the first-ever USL-MLS cupset and becoming the first third-division club to hand an MLS club a loss. In front of nearly 1,500 fans at Negoesco Field at the University of San Francisco, the Seals handed eventual 1997 MLS Most Valuable Player, Preki, and the Kansas City Wizards their first loss to lower-division opposition. A brace by former Don Marquis White featuring goals in the first and 59th minute at his former collegiate ground proved decisive.

"I felt we had a good chance because I felt we matched up well against their defenders and we just played with a lot of heart and that’s what beat them today," White said. "We are going to win the next one, we are going all the way."

While they fell just short of going all the way, the Seals became the first USL club to reach the Semifinals of the U.S. Open Cup, downing USASA's San Jose Inter SC, the defending A-League champion Seattle Sounders, and MLS sides Kansas City Wizards and San Jose Clash along the way.

1999 (FINAL): Colorado Rapids 0 - 2 Rochester Raging Rhinos

In 1999, the USL A-League's Rochester Raging Rhinos made history, becoming the first USL club to lift the Lamar Hunt U.S. Open Cup. After finishing as runners-up in their inaugural season in 1996, the Rhinos finished the job three years later, leaving a quartet of MLS teams in their wake. The Rhinos defeated PDL side New York Freedom in the Second Round before reeling off four consecutive victories against MLS opposition in the Chicago Fire, Dallas Burn, Columbus Crew, and finally, Colorado Rapids.

Over 4,500 Rapids and Rhinos fans convened at Crew Stadium in Columbus, Ohio to witness American soccer history. Former indoor soccer star Doug Miller opened the scoring in the 65th minute before former United States international Yari Allnutt put the match away in the 90th minute.

"It was like, 'Look what we’re doing here!'" Rhinos defender Scott Schweitzer told ussoccer.com. “"We thought we should be in MLS. We're sold out every week. We had more fans coming out than a lot of the MLS teams did. A lot more."

2005 (Quarterfinals): Kansas City Wizards 1 - 3 Minnesota Thunder

After the NASL's Minnesota Kicks (1976-81) and Minnesota Strikers (1984-88), the next professional team to grace the Land of 10,000 Lakes was the Minnesota Thunder. In 2005, the Thunder constructed the best U.S. Open Cup run of their existence, advancing past three MLS teams in succession to finish in the Semifinals. Minnesota dominated Real Salt Lake, the Colorado Rapids and the Kansas City Wizards en route to the Semifinals, outscoring the MLS trio by a combined 13-6.

Against the 2004 MLS Cup runners-up at Julian Field in Parkville, Mo., the Thunder - which featured a trio of former Kansas City players - downed the Wizards in front of 1,500. Liberia international Johnny Menyongar netted a 25-minute brace before a Wizards own goal early in the second half settled the issue.

The Thunder's magical cup run would end in Carson, Calif., as the USL First Division side fell to Landon Donovan and the LA Galaxy.

"We became giant killers that season," former Wizards draftee and Thunder defender Kevin Friedland told ussoccer.com. "Outside of the Rochester Rhinos in '99, no lower division team had really made a dent in that many MLS teams."

2007 (Quarterfinals): Seattle Sounders FC 5 - 0 Colorado Rapids

2012 (QUARTERFINALS): Michigan Bucks 3 - 2 Chicago Fire (A.E.T.)

The last time a USL League Two side enjoyed a victory against MLS opposition was back in 2012 when the Michigan Bucks - now Flint City Bucks - stunned the Chicago Fire at the indoor Ultimate Soccer Arenas in Pontiac, Mich in the Third Round of the tournament. The victory earned the Bucks the distinction of becoming the only amateur team to feature multiple victories against MLS opposition on their résumé.

Michigan raced out to a 1-0 lead through Tommy Catalano's ninth-minute goal, but the Fire responded to take a 2-1 lead by the 51st minute. The Bucks bounced back late in the second half, as Nate Boyden headed in the equalizing score in the 79th minute. Just three minutes into extra time, Bosnian winger Nermin Crnkić smashed in the eventual winner off of the hands of the Fire's goalkeeper, and the Bucks weathered the Fire's press for the remaining 27 minutes to see out the historic victory.

2017 (Round of 32): FC Cincinnati 1 - 0 Columbus Crew

One of the most captivating rivalries in MLS got its start in the U.S. Open Cup back in 2017. The Hell is Real Derby between then-USL side FC Cincinnati and MLS original Columbus Crew began in front of over 30,000 people at Cincinnati's Nippert Stadium in the Round of 32 of the 2017 U.S. Open Cup.

Against a Crew side featuring nine starters, FCC limited the Columbus attack before former Senegal international Djiby Fall headed in the eventual winner in the 64th minute to the delight of the crowd.

That crowd at Nippert Stadium - specifically 30,160 - served as the largest attendance figure for a non-final U.S. Open Cup match in tournament history. At the time, the match was also the third-highest-attended U.S. Open Cup match in the tournament's modern era and was the second-highest-attended match in club history.

"It's Cincinnati against Columbus," FCC Head Coach Alan Koch said. "People can break it down and say, 'It's the first game, so how do you have a rivalry?' Of course we have a rivalry. This is professional soccer, and when you get to play against teams that are this close geographically, it's very important for the clubs, our fans and both of our cities."

"This is what makes soccer special," then-Columbus Head Coach Gregg Berhalter said. "It's great to give Americans a taste of a real cup atmosphere – that's exactly what it was. Our fans were amazing, their fans were amazing and it made an atmosphere that was electric."

2022 (Third Round): Chicago Fire FC 2 - 2 (4 - 5) Union Omaha

On a cool April night at Soldier Field, defending USL League One champions Union Omaha defeated Chicago Fire FC in the former's first-ever penalty shootout. The match also marked the first time a League One team faced an MLS team in competitive play.

The Fire scored no goals from open play on the evening as the four-time U.S. Open Cup champions relied on a pair of penalties to challenge the visitors. Chicago opened the scoring with a Rafael Czichos penalty following a Joseph Brito foul in the box in the 53rd minute. The Union Omaha equalizer – the first goal against an MLS opponent in league history – came via a Noe Meza rocket to the far post from the right side of the penalty area.

Knotted up after regulation, the Fire seemingly clinched their spot in the Round of 32 following another converted penalty from Czichos in the 115th minute. However, an incredible Alexander Touche equalizer in stoppage time of the second extra time period extended Omaha’s chances of pulling off the upset. Taking the Fire to a penalty shootout, Dion Acoff would be the Owl to seal one of the greatest cupsets in league history.

2022 (Third Round): Real Salt Lake 0 - 1 Northern Colorado Hailstorm FC

On the second night of the Third Round of the 2022 U.S. Open Cup, first-year USL League One club Northern Colorado Hailstorm FC became the second League One side to defeat an MLS opponent, taking down Real Salt Lake 1-0 at Rio Tinto Stadium. In just its fourth competitive match of its existence, the Hailstorm bested the MLS club on the road, advancing to the Round of 32.

RSL dominated the match, but the Northern Colorado defense limited each of the host's attacks. With just one shot on target on the evening, Northern Colorado made it count as the veteran captain Robert Cornwall unleashed a sensational volley from the top of the penalty area to stun the RSL faithful. Despite nine minutes of stoppage time, the visitors held on to their one-score advantage, earning Northern Colorado Hailstorm FC one of the most impressive victories in League One history.

"This one is even sweeter," said Hailstorm Head Coach Éamon Zayed, "I'm so, so proud of our players tonight. They brought everything, every ounce of effort, every ounce of fight. They were solid; we talked about it, and we had a game plan. We wanted to remain compact and hard to break down."

2022 (Semifinals): Sacramento Republic FC 0 - 0 (5 - 4) Sporting Kansas City

Of the 13 USL-MLS cupsets we were treated to between 2022 and 2023, one of the most memorable has to be Sacramento Republic FC's triumph against four-time U.S. Open Cup champion Sporting Kansas City in the Semifinals of the 2022 edition of the tournament.

Republic FC's improbable, indomitable cup run started with victories against clubs from each of the USL's three men's leagues in Portland Timbers U-23 (USL League Two), Central Valley Fuego FC (USL League One) and Phoenix Rising FC (USL Championship), and was defined by victories against three MLS teams in the San Jose Earthquakes, LA Galaxy and Sporting Kansas City.

Scoreless through 120 minutes in front of a rowdy 11,500 fans at Heart Health Park, Sacramento absorbed a relentless SKC attack which featured 31 shots and 60% possession in favor of the visitors. Republic FC goalkeeper Danny Vitiello constructed a legendary performance, recording eight saves across 120 minutes to keep a clean sheet before making a clutch save on Graham Zusi's fifth penalty of the shootout. Captain Rodrigo López's winning penalty kick in the fifth round of the shootout sent the crowd into a frenzy and Republic FC into the final.

On that special night in Sacramento, Republic FC became the first USL club to advance to the U.S. Open Cup Final since the Charleston Battery of the USL First Division advanced to 2008 U.S. Open Cup Final.

"The boys gave everything and we rode our luck at times, which you have to do against MLS sides," Sacramento Head Coach Mark Briggs said.

"It was a disappointing match tonight that I thought we did more than enough to get the result that we needed, but that's the game sometimes," Sporting Kansas City Manager Peter Vermes said. "It happens around the world. This is why this cup is such a great competition. I loved playing in it as a player and I loved coaching it."