When you buy a beer at a baseball game, there is one unwritten rule that must always be followed: If a ball lands in your cup, you must chug whatever is left before removing it.

One lucky fan at Monday’s game between the Cubs and Reds honored the time-old tradition after a foul ball from Chicago’s Alfonso Rivas found his drink during the third inning. He acknowledged the crowd and raised his cup before downing the rest of his beverage with the ball snuggled at the bottom.

The best part about it was that the fan got the souvenir effortlessly, as the ball landed perfectly in the cup. The folks around him gave him the heads up before he even realized it was in there.

And don’t worry, some say the ball gives the beer a little extra flavor.