webdriver findelement by xpath <a> <span> C# -

i need create test in webdriver c# click link "text" in menu has structure this:

<ul style="overflow: hidden">     <li>         <ul class"menu" style="overflow: hidden">             <li class="class_li">                 <a href="/level1/leve2">                     <span class="class_span">text</span>                 </a>             </li>         </ul>      </li>     <li />     <li /> </ul> 

classes ""class_li" , "class_span" used many times. cannot modify html code.

i tried few different xpath statements everytime got "invalidselectorexception unhandled". how can link , click it?

the following xpath select first a link has direct child span text text

(//a[span/text()='text'])[1] 

i'm no selenium expert, should able this:

driver.findelement(by.xpath("(//a[span/text()='text'])[1]")).click();