I am trying to automate clicking on a button of a webpage where the source code has the following structure: 

    <div id="ctl02_" class="sel">
       <div id="Lo" class="cont">       
          <div class="cl">         
             <span onclick="__doPostBack('ct$ctl00','M_CC_1')" 
               class="fakeLink" title="add &quot;D&quot;"> 
               <img src="Skin/D.png" alt="add &quot;D&quot;" class="io" 
               />&nbsp;D</span> <br />

I am currently trying to accomplish this with the use of python and Selenium. Below you can find how I am trying to do this: 

    driver = webdriver.Firefox()
    driver.wait = WebDriverWait(driver, 5)
    driver.get("http://www.thewebpageIwanttoclickforwardto.com")
  
    try:
       elem = driver.wait.until(EC.presence_of_element_located((By.XPATH, "//div[@class='cl']")))
       
    except TimeoutException:
        print("Element not found")

    elem.click()

The program finishes fine (exit code 0), however, the webdriver has not moved to the webpage behind the click (which I would encounter if I would physically click on the button D on the webpage). I have tried many things giving me the feeling that I am missing something basic here. 

Where am I going wrong here? Am I using Selenium in a wrong way here? Or is Selenium not the right tool for this?