An MLB game was paused for several moments Monday night ... after a fan ran onto the field and pretended to throw pitches on the mound.
The bizarre scene all went down during the Mets vs. Giants game at Oracle Park in San Francisco ... when a guy in a Padres jersey bolted from his seat and jumped onto the field.
You can see in footage from the ballpark ... the guy ran around the infield grass for several seconds before he hopped onto the bump and went through an entire pre-pitch routine.