After hitting and waiting the golf ball going towards the green. The golf land on the green and roll and disappear, as we were headed to the green, we were not able to find any balls on the green and walk to the back of the green to look for balls. Found my partner ball rolled off the back of the green as he's only using a 9 iron, so we thought mine might rolls off too as I am hitting a 7 iron. Unable to find my ball an there is rough at the back of the green, so I drop another ball and chip on the golf. When trying to line up for putting and walking pass the cup, I notice my ball was in the cup.