Juggernaut can't touch Barry, Barry can't hurt Juggernaut. But he could send him miles away, I think. Or banish him to the Speed Force like what Wally and Bart did to Superboy Prime (can they still do that?)
If BFR counts, Barry takes it. He could taunt Juggernaut into a rampage, and then feed him with extra kinetic energy so he rampages uncontrollably in a random direction until he's removed from the battlefield.