The Portugal vs. Uruguay World Cup match was interrupted by an unexpected intruder on Monday ... when a man holding a rainbow flag stormed the pitch in protest.
The spectator made his move 50 minutes into the contest ... running at full speed before getting stopped by security and escorted off the grass.
Along with the rainbow flag, the man was wearing a Superman shirt that read "Save Ukraine" on the front ... and "Respect For Iranian Women" on the back.
Of course, homosexuality is illegal in Qatar .