Patch Hole in Block Basement Wall

Hope someone can give me some advice on the easiest way to do this!

I just removed a rusted & broken galvinized sump pump drain line from my basement wall (long story from another post). There is now an irregular shaped hole through the block wall that needs to be patched. The hole is approx 3" in diameter and goes through the thinnest part of the block. There isn't enough surface on the base of the block to simply start piling up the cement and fill in the hole. The make matters worse, the I can't put any type of backer behind the hole because it will just drop down through the inside of the block and the block(s) directly beneath. Also, I would like to patch the outside section of the block as well. Unfortunately it's under a cement slab so it's not possible to dig up the dirt and patch it from the outside.

Any suggestions on methods and materials I can use to patch this up? Thanks!!!

 

Not really sophisticated, but pack crumpled newspaper down into the hole to support the filler concrete.

 

I will give it a try tomorrow! Thanks.