As I recall, the Twins beat the Yankees regularly whenever I attended a game in the 60s. This day was no exception. Notably, I saw two HOFers and one almost in Tony Oliva on this day. Link to box score at Baseball Research
Harmon Killebrew
May 25, 1969 – Yankees vs. Twins
A Sunday doubleheader – two chances for the Yankees to lose to the Twins and they did it! It just seems they always lost to the Twins back then… Link to box score for game 1 at Baseball Research Link to box score for game 2 at Baseball Research