Well, the Maracana stadium in Brazil used to hold 200,000, and was SRO during the 1950 final.
Admittedly, 25,000 is kinda small for a soccer stadium.
In the U.S. on a collage football Saturday, you don't have to wait until the playoffs to fill up the stadiums. Almost every Bama home game fills their 100K+ stadium during the regular season. As do Michigan home games, and Texas A&M home games, and Vols home games, and Ohio State home games, etc.
Every football Saturday has multiple 100K+ stadiums full on the same day. I'm not even talking about playoffs or conference championships or bowl games. I'm talking about regular season games.