George Thorogood Tells Mick Jagger to 'Suck On That' After Show

Drake vs. Kendrick? Cute. The real heavyweight grudge match is in the senior circuit ...  'cause Mick Jagger’s new nemesis seems to be none other than George freakin' Thorogood!

Yup, TMZ snagged the vid -- 75-year-old blues-rock legend George exited Houston’s House of Blues Wednesday following his show with The Destroyers ... only to turn back, eye a fan and drop the line ... "You tell Mick Jagger he can suck on that," pointing at the venue behind him, to a few supportive cheers, with one onlooker exclaiming "U-S-A!"

For the record -- there’s zero known beef between the "Bad to the Bone" singer and 82-year-old Mick. So either George was flexing to claim he's the boss, straight-up trolling for kicks, or just tossing Mick's name out at random 'cause of an adrenaline high.

Either way, nobody really poked the bear here, but he seemed very desperate to drop that Jagger jab before rolling away on his tour bus!

But ya never know ... we might be witnessing the birth of rock’s grumpiest grudge match, and if Mick claps back, you'll have to be ready for the ultimate Battle of the Old-Timers!