Manny Machado Melted Down Over Dodgers Pitcher's Celebration, 'F*** You!'

Manny Machado lost his freakin' mind on the diamond Wednesday night -- going on an F-bomb-laced tirade ... and it's all 'cause a Dodgers pitcher celebrated a great defensive play.

Here's the deal ... in the 7th inning of Game 2 of San Diego's playoff series with L.A. -- Brusdar Graterol took the mound to try to help close things out for the Dodgers.

The problem? He let a fastball out over the middle of the plate that Fernando Tatis Jr. CRUSHED -- and it looked like a no-doubter, 2-run bomb that would give the Pads a 5-4 lead.

But, centerfielder Cody Bellinger saved the day ... robbing the HR with ease -- and Graterol went NUTS!!!

Brusdar threw his glove with joy, then tossed his hat, then fist-pumped ... and Machado (who had bat flipped the hell out of a homer earlier in the game) hated ALL. OF. IT.

The former Dodger melted down on the diamond, telling Graterol "F*ck you!" repeatedly, before adding, "I'll be waiting for you!"

Graterol soaked in the trash talk ... blowing the guy a kiss -- while the rest of his Dodgers teammates told Machado to sit down.

The next inning, Graterol went on to get Machado to ground out ... and the Dodgers eventually sweated out a 6-5 win to take a commanding 2-0 series lead.

Great theater.