Indeed Sasuke Sarutobi was the 3rd's father, but it is strange how we have not yet seen Konohamaru's father in the manga.
Asuma got a great deal of screen time as Konohamaru's uncle yet no mention of his father. Considering Konohamaru's character is being refined as a result of both his grandfather's and his uncle's death, I would think his father would be a driving factor in his pursuit of becoming Hokage. His father must have died before the series started, but he should still be important to his son's character.