Marlon Brando's First Wife -- War Over Final Resting Place

The first wife of Marlon Brando is turning over in her grave because her dying wish -- to be buried side-by-side with her son, Christian Brando -- was denied by Christian's first wife.

Anna Kashfi was laid to rest Wednesday in Kalama, WA after succumbing to breast and colon cancer. What friends planning her funeral didn't realize ... is that Mary Brando had snatched the prime real estate next to Christian's grave -- even though they'd divorced 21 years before his death.

Funeral organizers went to plan B, and instead buried Anna in the plot directly above Christian -- so they're now head-to-head.

Mary is still alive ... and Brando family sources tell us Anna's estate contacted her to try to buy back the prized plot, but she refused. That's more bad blood than a T. Swizzle video.