This is the only TMNT Series in history where the Turtles never defeated Shredder.

[Technogeek29]

Originally Posted by Powder

They will in the next 2 months. Nick's Shredder is actually competant. Let that sink in. There were times OT Shredder got beaten by Channel Six. & as far as 4kids' turtles go, they hadda become dragons to take down the original Shredder & later required the combined strength of 12 ninja turtles + Shredder/B&R to beat Ch'rell in Turtles Forever. Seriously, stop being a hater.

1st movie: Beaten by Splinter
2nd movie: Beaten by himself
Next Mutation: Beaten by Venus
PDTMNT1: Beaten by April
PDTMNT2: Beaten by Krang

So there's 5 iterations right off the bat where the turtles couldn't do it themselves. 6 if you count the aid they got in 4kids, 7 if you wanna be super nitpicky about the OT, 8 if I'm busting balls & remind you Splinter killed him in IDW, too.

Beat me to it.