The homecoming bout for Taylor ended in disappointment as Cameron retained her undisputed light-welterweight crown with a shock result.
One judge had it as a draw, while the other two both scored it 96-94 to Cameron.
The 32-year-old extended her own undefeated record to 18 wins while snapping Taylor's.
"If I'm honest, I wasn't expecting the decision to go my way," she told the BBC after her win.
"I'm over the moon it went my way."
Speaking on a likely rematch, the Briton was keen to stress she expects to be treated with more respect next time around.
"I need to speak to my team because everything was in Katie's favour in this fight," she said, having broken normal fight traditions by seeing her name second on the poster and making the first ring walk despite being the reigning champion.
Taylor was unable to hide her disappointment after the humbling defeat in front of a deflated hometown crowd.
"I was expecting a gruelling fight and that's what it was," she said.
"I obviously came up short. I always love a challenge and I'm looking forward to the rematch.
"This isn't how I wanted the homecoming to go but I'm grateful that this event could sell out in a couple of minutes."
For the 36-year-old Dubliner, it was a first loss since the 2016 Rio Olympics and her first as a professional.
Cameron was quick to push the pace during the fight, pouncing from the get-go and keeping up a relentless pace throughout the 10 rounds.
Taylor was able to demonstrate fast footwork and countering, as well as plenty of her trademark heart, but had little answer to Cameron's electric combinations, with the Englishwoman never really appearing troubled up until the final bell.
