I was playing with a friend of mine at the Robert Trent Jones Capitol Hill Judge course. We were playing the hole #6 par three which is an island green. There was a 2 club wind with yardage to the pin at 165 yards. I was playing a Pro V1x ball at the time. I used my rescue 4 club due to the wind coming across the lake. The ball land toward the middle of the green and rolled over the hill towards the cup and out of sight. We did not see the ball go into the hole due to the slope on the green. When we arrived up on the green I did not see my ball on the green. My friend started looking off the back side of the green but I knew that there was no way that the ball rolled off the back. I looked in the cup and found my Titleist ball there. This was my second hole in one, both were made playing Titleist Pro V1 balls.