David Ortiz Whiffs During Baseball-Themed Gender Reveal

Big Papi Suffers Big Fail During Gender Reveal ... Swing And A Miss!!!

SWING AND A MISS !!!

David Ortiz has finally met a pitcher who can blow a baseball by him ... and, it turns out, it's his girlfriend!!

The MLB legend learned that the hard way when he and his significant other, María Yeribell Martínez, were throwing a party recently to reveal the gender of their unborn baby.

The two came up with a baseball-themed plan to make the announcement ... where María would throw a pitch to Ortiz that he was then supposed to blast into either pink or blue smoke.

But, check out footage from the bash ... Ortiz -- a 10-time All-Star with 541 career home runs -- completely whiffed on María's inside heater!!

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