The British Masters super-middleweight champion looked to have hit his peak as a fighter but was shockingly halted in five rounds by Derby's dangerous but unheralded Elvis Dube last month.
The unscheduled setback, on a Pat Cowdell-promoted card in Birmingham, was Finnegan's first defeat in three years - and the popular Burton-on-Trent scrapper gets the opportunity to even the score when the pair meet for a second time on May 23, again in the Second City.
Shinfield-handled Dube's record may be patchy (a brace of wins in nine) but both his victories have arrived inside the distance and he always comes looking for a fight.
And he clawed his way back from being soundly out-boxed over the opening four rounds to drop the 30-year-old former Irish light-heavyweight title challenger with seconds remaining in the fifth of a set six.
Despite the always-brave Finnegan managing to find his to his feet, referee Sean Messer waived it off - handing the Errol Johnson-trained stylist his sixth defeat as a professional (13 wins, three draws).
The manner of the defeat clearly frustrates Jonjo, who was looking forward to topping a bumper bill in his hometown. He said: "It was a poor stoppage.
"I was clearly winning the fight - had won all the rounds leading up till the fifth - but got caught with a silly shot. That's boxing. But i was up at four, my head was clear and i was ready to carry on.
"There was only a few seconds left so i should have been allowed to carry on," reasoned a popular Midlander who won the British Masters 12st strap with a grueling ten-round decision over a man he once drew with, Sheffield bin man Dean Walker.
"As soon as i left the ring i spoke to Errol and he's got me the only fight i wanted - a rematch with Dube, on May 23. He's the only person on my mind and this time i will set the record straight," roared the former Midland ABA champion."