Lighting, Light Fixtures, Ceiling and Exhaust Fans - Dimmers again

Trying to connect a Levitron dimmer and I am doing a poor job. I have two cables coming into the box and the switch is single pole. The dimmer has a black wire, red wire, 2nd black wire for three way {which I have capped} and a green ground.

I have a white wire, black wire and ground coming out of one cable and a black wire, white wire, red wire and ground out of the other. I have attached the green wire to the two grounds, the two white wires to each other {neutral} and have tried every combination of attaching the red and black from the dimmer I can think of to the two black wires from the cable. A few of the combinations will turn the fixture on when powered up but it does not turn off nor dim.

The instructions are great if you only have one cable coming in but give no explanation for the two cable scheme.

As a matter of reference the switch I removed use the two black wires attached to the box itself and worked fine.

Thanks for your help.

Very simple. Take the 2 black wires off your switch and connect them to your dimmer. Don't mess with any other wires in the box except the grounds(bare). Connect them to the green wire.

Thanks for the direction... I have attached the black wire from the dimmer to one black wire and the red wire from the dimmer to the other black wire in both combinations ... to no avail. what would the exact wire connections be??

Thanks for your help...Ottawa boy here {living in Florida} ... but definitely not an electrician.