Regional provided trainer Ed Bethell and jockey Callum Rodriguez with the first Group One success of their careers in the Betfair Sprint Cup at Haydock, in which hot favourite Shaquille finished last.
Shaquille had missed the break in both the Commonwealth Cup and July Cup before storming home to win, did not look happy before the race.
He had tried to unship James Doyle on the way to the start and then did not want to go in the stalls until Doyle jumped off.
He did break on terms on this occasion and soon found himself in front, at which point connections would have been delighted, but with two furlongs to run Shaquille had no more to give and Doyle looked after him.
Regional (10-1), who had been making his name over five furlongs and needed to prove he could beat the best over six, faced a strong challenge from 50-1 outsider Shouldvebeenaring but held on by a neck, with the supplemented Believing back in third.