Tampa Bay Rays center fielder Kevin Kiermaier ROBBED Red Sox rookie Jonathan Arauz of his first career hit with a miraculous catch on Monday … and you know who was super-pissed about it??

Sox first baseman Michael Chavis — who straight-up gave Kiermaier a one-finger salute after making the highlight play!!

The hilarious interaction was caught on camera … when Kiermaier leaped to catch Arauz’s deep shot to center field in the 2nd inning.

Chavis made his frustrations known by getting KK’s attention from the dugout … just to give him a solid middle finger!!

So, why is Chavis so mad?? If Kiermaier hadn’t come up with the ball, 22-year-old Arauz would have notched his first MLB hit … but of course, that didn’t happen.

It all ended up okay in the end for Arauz — he finished the game with 3 hits as the Red Sox fell to the Rays, 8-7.

The birds have been flyin’ since the season kicked off last month — as we previously reported,  Arizona Diamondbacks closer Archie Bradley appeared to flip off the Houston Astros last week … which, of course, is completely understandable.