After coming off previous hole with a bogey, both Brian & Steve hit their shots straight into the green leaving good putts for pars or birdies. Looked at the yardage and took a 9iron and decided to go straight at the hole rather than slightly to the right as the hole slopes to the left. As the ball left the club the sun was shinning down and could not see where it landed. Then all we heard was a loud bang and the thinking what was that where did my ball go as did not see it bounce. When walking up to the green Brian said I wonder if it went straight in joking around and then when I looked in the cup there it was sitting snug. I had noticed the mound bang was the ball hitting the very base of the flag/cup in the hole as it left a ball mark. With the biggest grin celebrating my very first hole in one.