The Tickhill fighter delivered a brutal performance to overwhelm Doncaster rival Daniel Slaney inside seven rounds and become Central Area super middleweight king in only his sixth fight.
Much of the attention - and pre-fight tipping - had fallen on Harworth's Slaney, who commanded the greater profile and stood in the home corner hoping to ignite a promising career.
But Thomas - who has operated away from Doncaster for much of his career - pummelled his way into prominence with a dominant show that upset the apple cart on Stefy Bull's brilliant show at The Dome.
Thomas pounced on Slaney from the first bell, unloading shots to which there was little answer from the Harworth maths teacher.
Slaney was in trouble and struggled to weather the early storm in an opening round which firmly went against the plan.
Thomas was the aggressor in the second and the uncomfortable Slaney barely offered any offense in return.
The southpaw did begin to find his feet in the third and did enough to suggest he could turn the fight around as he began to work behind the jab.
But any shift in balance was short-lived. Whenever 31-year-old Thomas turned up the heat and piled forward, Slaney could not handle it.
Clubbing shots troubled Slaney and halted any progress he made with the jab and on the inside.
The end was in sight early in the sixth when a stiff short right hand from Thomas sent Slaney tumbling back through the ropes.
Though Slaney made the count, his eyes were glazed over and Thomas smelled blood.
He pounced quickly and sent in a string of shots which Slaney could not block.
Referee John Latham took a quick look and began a standing count but waved the fight off quickly.
Thomas' manager Joe Elfidh was delighted with his man's performance.
"They underestimated him and he have it is all," he said.
"So many people told me, naming no names, that he didn't have a chance of winning that title and I don't know if anyone has ever won an Area title in their sixth fight before.
"He was in the away corner but sold a few tickets anyway, being a Doncaster boy.
"He's a pleasure to work with and I don't think anyone from Tickhill has ever achieved this before.
"He's hardworking in the gym and never says no to any fight. He's not bothered about boxing in the away corner.
"He's so naturally heavy-handed with both hands.
"What's next for Richard is that he likes being up against it so we'll look for a big name next."