list child category latest post titles!

I have a nav bar that I would like to list the titles of the latest posts in the 3 child categories of one parent category.

Basically i have one category Portfolio. The 3 child categories are Portfolio1, Portfolio2, and Portfolio3.

I would like to list the following:
title one of the latest post in Portfolio1, title one of the latest post in Portfolio2, title one of the latest post in Portfolio3

Right now all i can figure out is how to list the titles of the 3 child categories:
<?php wp_list_cats(‘sort_column=id&optioncount=0&use_desc_for_title=0&child_of=4’); ?>

Anyone know how to do this?

Thanks!