After making a running catch near the stands, Nicholas Castellanos gave a very excited Tigers fan a high-five

Let this be a PSA to fans at ballparks: If you sit along the right-field or left-field lines, be sure to pay attention and not interfere with balls in play, should any head in your direction. An Astros fan in Houston last week found out the hard way why this is a bad idea.
On the other side of this scenario, though, is the fan who gets rewarded for not impeding the flow of the unfolding play in front of him -- like this guy in choice box seats for the Tigers' 5-4 win over the White Sox on Friday night. 
Nick Castellanos made a running catch for the first out of the sixth inning, his momentum carrying him toward the stands. The Tigers fan in question was very excited about everything happening right in front of him ... and so was Castellanos: 

With that level of effort, Castellanos earned that high-five, for sure. The moment also warranted some laughter, as well:

Kudos to everyone involved for a fantastic sequence of events.