How to select SuperTab completion suggestion without creating new line?

When I hit Enter on SuperTab's popup suggestion, it automatically creates a new line at the end of the inserted keyword.

Is it possible to select an option in the SuperTab popup without creating a new line?

More specifically, is there a way for me to configure space as the method of selecting the code completion suggestion?

inoremap <expr> <Space> pumvisible() ? "\<C-y>" : " "

Note the <C-y> that accepts currently selected option, you may want to use it directly instead of remapping space. You will see more in :h popupmenu-keys.