36-year-old Brunson handed 22-year-old Shahbazyan the first L of his career at UFC Fight Night in Vegas last Saturday via a 3rd-round TKO.

But, many people believe Edmen -- who ate a flurry of heavy punches to end the 2nd-round -- shouldn't have been allowed by his corner, the ref, or the cage side doctor to come out for the 3rd round.

After the fight, even Dana White criticized the doctor for taking too long to make a decision between rounds ... and said the fight "could have been stopped."

There is at least 1 guy who thinks everyone involved made the right decision ... and that's Derek Brunson, who tells TMZ Sports Shahbazyan was still very much in the fight.

"I mean, of course, they have to [let Edmen continue]. They could of thought it was 1 to 1 [on the scorecards]."

Brunson continued ... "I thought I won both rounds but still, it was relatively close so you can't stop a fight there yet. It's one of those things in sports, you gotta suck it up at that point, ya know?"

Ref Herb Dean eventually stopped the fight only 26 seconds into the 3rd round ... giving DB his 3rd straight victory.

So, who does Brunson -- who was the 8th ranked UFC middleweight BEFORE his big win of ES -- want next?

"The best fight for me next is probably Jack Hermansson. Very tough guy, he's riding a hot streak. I seen him trying to pick fights with Darren Till, but that's not the fight. Me vs. Hermansson, that's the fight to make. I need to crack that top 5."

32-year-old Hermansson is coming off a super impressive 1st-round win over Kelvin Gastelum.

And after Hermansson? Brunson has his eyes on Israel Adesanya ... and he says this time will be very different than when they scrapped in 2018.