Flex-box: Align last row to grid

Flex-box: Align last row to grid

I have a simple flex-box layout with a container like:
.grid {
display: flex;
flex-flow: row wrap;
justify-content: space-between;
}
Now I want the items in the last row to be aligned with the other.
justify-content: space-between; should be used because the width and
height of the grid can be adjusted.
Currently it looks like

Here, I want the item in the bottom right to be in the "middle column".
What is the simplest way to accomplish that? Here is a small jsfiddle that
shows this behaviour.