Michelle Obama raced to Simone Biles' defense Tuesday ... praising her for bowing to her competitor on an Olympics podium this week -- just hours after an NFL star called the act "disgusting."
Biles -- alongside her Team USA squadmate, Jordan Chiles -- bent the knee for Rebeca Andrade following the Brazilian's win in Paris on Monday in the floor event ... and Baltimore Ravens corner Marlon Humphrey was pissed over it.