England captain admits victory in South Africa would be his biggest achievement to date.
England head to the Wanderers on Friday leading 2-1 and looking to wrap up an overall series success.
The victory would be all the more pleasing for the skipper due to the amount of injury and illness disruption they have faced.
The squad was first struck down with sickness ahead of the first Test before Rory Burns and James Anderson were ruled out with injury.
Jofra Archer has also been carrying a knock and Jack Leach was forced home after being hit the hardest by illness.
Asked if it would be his biggest achievement as skipper, Root said: “I think it probably would be yes, because of the different things we’ve had to manage throughout this tour.
“We’ve had injuries with senior players having to fly home and a lot of illness to deal with. And we have adapted to very different conditions and for a very young group of players to manage that has been very pleasing and a sign we’re doing the right things.”
England are priced at 1.83 (5/6) with bet365 to win in Johannesburg. South African are available at 4.00 (3/1), with the draw at 3.75 (11/4).
Captain believes there is much more to come
Root also thinks landing the win can be the start of bigger things for his young group of players.
He added: “The sky’s the limit for this team.
“But I do think we’re very much at the start of something here and we’re not perfect by any means. We have to keep that attitude and keep driving that forward for a long period of time if we want to get to number one in the world.”
Of those young players, England fans will be keen to see more of Ollie Pope in Johannesburg.
His unbeaten 135 in Port Elizabeth set up the previous victory.
Root praised the young batsman after that win, saying: “He is a wonderful talent and has such a brilliant game on him.
“For him to do it this week was a massive marker for himself and Test cricket in general. A very talented young player has shown he is ready for this and he wants to be very hungry for runs and make it count when he gets in.”