Mike Swain made history in 1987 by winning the Judo World Championships, the first American to do so. He faced off against the 20 year old Koga in the quarterfinals of that tournament, and threw him twice for what I would argue to be an ippon (but both times was called a wazari). In their next two meetings, Koga ended up the victor, but this single match to me represents a great accomplishment, and even if you didn’t know the two people fighting, it’s still a fun match to watch. I couldn’t find it on YouTube, so I decided to upload it:
And of course, as if you needed proof, here’s a highlight of Koga later in his career.