Styling the first paragraph differently in single.php

Hello,

I am working on my single.php template and I have run into a brick wall. I want to style the first paragraph of each post differently from the rest of the content, but only in single post view. I’d like to do so automatically via the template file without having to insert the appropriate class manually each time a post is written in the back end.

I have disabled the wordpress automatic paragraphs feature and would like to avoid using CSS3 pseudo-classes, to avoid cross-browser compatibility issues with IE.

Any hints or ideas on how to best approach this problem?