[SOLVED] Span Tag in Post Title screwing with Display in Excerpt Title

I inserted a span tag around a single word in the TITLE of my blog post so it would appear smaller than the rest of the text. The tag works fine for all purposes except when displayed as an excerpt. Then the tag interferes with, I'm guessing, some other preset function or setting.

Here's what is typed into the TITLE line in the Edit Post area:

Attached is how that title appears when the post is displayed as an excerpt.

Any way I can work around this so I can keep the tag?

Thanks.