MLS: US Open Cup-Columbus Crew at Pittsburgh Riverhounds SC
Charles LeClaire / USA TODAY Sports

The only thing better than one 'Cupset' is two, as the Pittsburgh Riverhounds and Birmingham Legion will carry the USL Championship flag into the quarterfinals of the U.S. Open Cup.  

Bob Lilley led the Pittsburgh Riverhounds to a 1-0 victory over the Columbus Crew, while the Birmingham Leigon defeated 10-man Charlotte FC 1-0. The Riverhounds will qualify for the quarterfinals for the first time since 2001, while the Legion qualify for the first time in franchise history.

Following in the footsteps of Sacramento Republic, who made the Open Cup final last season, both teams have ensured that the USL Championship flag will fly in the quarterfinals.

Once Albert Dikwa opened the scoring in the 22nd minute, the Riverhounds held on against a rotated Crew side which now follows Los Angeles FC of top teams to fall out of the cup. Having knocked the New England Revolution out of Open Cup, Lilley's RIverhounds are now on a seven-match unbeaten run in all competitions. They had to hold on after Edward Kizza was sent off in stoppage time but were able to do it.  

The Riverhounds become the first USL Championship team to win back-to-back shutouts over MLS sides. With the bracket set by region for the next round, the Riverhounds will face FC Cincinnati in the quarterfinals as they look to knock out three MLS sides in a row. 

For Birmingham, it took until Charlotte FC defender Adilson Malanda was sent off in the 51st minute to score a goal, and it had some MLS flavor with former New England Revolution player Juan Aguedelo assisting Prosper Kassim's finish.

The Legion have been a club on the ups in USL under the leadership of general manager Jay Heaps, and this is a landmark moment for the club. In the quarterfinals, they'll face Inter Miami, meaning that there is also a chance that Birmingham and Pittsburgh will square off to ensure consecutive Open Cups with a USL Championship side in the final. It's a testament to the growth in American soccer that second-division sides are going further and further in America's longest-running soccer competition.