Web Page section loading timings capture

We have the web timing api which is a great java script api's available to capture the page load time , and same has been stated by W3C in here... It works great and return the page loading timing readings , when the entire page loads or refreshes...

But do not serve the purpose when a section of the web page alone is loaded due to a AJAX or by some other technique

Do we have any other api's or any other way to find out the timings when a portion of a web page alone is loaded and updated data , with out the entire page is loaded

Thanks a lot

Musaffir