This is definitely a favorite picture of mine, and is a good example of paying attention to what is happening in the match in order to catch a dramatic photo.
This match was the semifinals of the 2008 Australian Open, in which Justin Han (pictured) was playing against Shibaji Datta. After a good start by Justin, Shibaji was starting to get on top in the final stages of the match, and Justin was getting frustrated.

This was starting to show up in his on-court demeanor and his reactions when losing a point, so I figured that there would be a good chance that Justin might do something interesting if he lost an important point. On the other hand, Shibaji was being quite cool and collected, so it didn't look like he would be doing anything too noteworthy if he won a good point. So I thought I would stick with Justin for a while, since there seemed to be a better chance that he might do something worth capturing in a photo.

And so it proved, with Shibaji winning a big point to virtually cement the win, and Justin lifting his leg high in the air, looking like he was going to bring it crashing down onto the table. In the end, he changed his mind and stamped on the floor, but it still provided a picture that you don't see every day!