Awk-ward: Agassi & Sampras

The rivalry between Pete Sampras and Andre Agassi is still going strong - even at charity matches.

Sampras, paired up with Roger Federer, took on Agassi and Rafael Nadal at the "Hit for Haiti" charity match in Indian Wells, California on Friday night. And the two retired rivals were not about to let a good cause get in the way of their petty feuding.

As the match wore on, the competitive juices started flowing, and things got pretty damn uncomfortable with Agassi and Sampras starting to take shots (literally, even!) at each other.

Observe:

In his autobiography Open, Agassi had mentioned Sampras' poor tipping, which is what that whole thing was all about.