Of course, not every match is played between two close friends, but today we had two such semifinals - one in Stuttgart (Caro vs. Aga) and one in Barcelona (Daveed vs. Nico).
I think that tennis is quite unique in the respect players show each other. For kids playing tennis, walking up to shake your opponent's hand, no matter whether you won or lost, is surely an important experience, which helps them deal better with successes or failures later in life. The pros, however, do it on quite a different level, in my opinion. So watching them fight out the match, and still be able to show that appreciation is really endearing.
(Top two photos by Alex Grimm/Bongarts/Getty Images. Sorry for the slightly crappy quality of the last one, it's a printscreen from the TennisTV stream)