Mark Wood, who was in doubt on the first morning, registered his Test best figures of 9 for 100 in Johannesburg © AFP

Even as late as the warm-ups on the first morning of the final Test at the Wanderers, Mark Wood's participation was still in doubt. He had pulled up sore after the previous game in Port Elizabeth, his first competitive action since the World Cup final at Lord's last July, and did not know if he was going to be able to get through the game. Wood knew it would be a risk to play him but he gave Joe Root and Chris Silverwood the option of selecting him anyway. You can bet they are pleased they took that risk now.

Wood registered his Test best figures of 9 for 100 in Johannesburg bowling with pace and aggression and no little skill. He showed few ill effects from the previous Test and following his five wicket-haul in the first innings, when South Africa were bundled out for 183, he made two key breakthroughs on the final day by dismissing Rassie van der Dussen and Quinton de Kock as England wrapped up a victory by 191 runs.

"We made some very strong calls, took it out of players' hands and made sure we gave Woody, for example, every opportunity to succeed," Root said to Sky Sports at the end of the match. "You watched him bowl and, of course he was feeling it but he was still able to deliver his skills, and still coming out at a good pace.

"We knew he'd be able to get over it during the course of the game and, with five seamers, we could sort of manage him through the first day if we ended up having to bowl first. It was a calculated risk but, the confidence he had coming in from the last game, it was quite an easy decision."

Wood and his Durham teammate Ben Stokes got England moving just before tea on the fourth and final day after the home side has displayed plenty of fight during the opening two sessions. First, Faf du Plessis was bowled by a Stokes delivery that kept fiendishly low and then in the next over, Wood removed van der Dussen, caught at short cover for 98.

It was a double blow which knocked the stuffing out of South Africa and despite some lower order hitting, it took England just another 18 overs to take the six wickets needed to secure victory. "He has got a huge amount of energy and just before tea the two Durham lads showed a huge amount of fight and did exactly what we needed, with nothing more than just desire and will to get a wicket," said Root.

"I think that's an area we've really improved on. It takes more than just skill to take wickets, you've got to have something else - it's an attitude. We definitely delivered that just before tea and it made a big difference going into the last session."

Despite his strong showings on this tour, Silverwood admitted that England will have to look after Wood given his injury record. "We will make to make decisions based on what's best for him," Silverwood said. "We will look at how he trains as well, making sure he's not wasting all his best deliveries in the nets. Whatever he does, he does it 100 percent. So can we tailor his training to make sure that his best effort goes out on the pitch for us, and equally when he needs to rest, we'll know we've got a backup with Jofra [Archer] and others to come in."

"It's a great headache to have for Rooty as captain and me as head coach. In an ideal situation, we'd like to have two or three fast bowlers kicking around but we don't have to play them every game. In this Test, Woody comes in and makes an impact, but another day, we can give him a day off because we've got Jofra coming in now."

England's victory was just their second overseas series win in the past four years. Achieved with a young group, and missing a number of first choice players because of injury, it has been an important step forward for Root and his squad. After the three ODIs and three T20Is against South Africa, England will head to Sri Lanka for two Tests where they will look to continue their improvement.

"We made it very clear at the start of the winter how we wanted to play, and that has not changed at all; keep things very simple, make big first-innings runs and then try and drive the game forward with the ball," Root said. "It has been really pleasing seeing the guys go out and deliver that.

"That will be a big focus for us moving forward, wherever we are in the world. We'll have slightly different strategies of doing it but, as a template, the last couple of games are pretty much where we want to be. It gives us a huge amount of confidence. It's really nice to know that with everything we've put in place, we're thinking the right things."

Part of the template that has succeeded has been a batting group which has delivered consecutive first innings totals of 400 or more in Port Elizabeth and Johannesburg. England had passed 400 just once in their first innings in their previous 25 Tests and doing it more consistently is something Silverwood has placed a big focus on. "To get a batting order that has the ability to get big first-innings runs, you need to create a variation in how they are going to play," he said.

"You can see the one, two, three we've got [Dom Sibley, Zak Crawley and Joe Denly] go about things in their way which is completely different to how Rooty, Stokes, [Ollie] Pope and [Jos] Buttler will go about their business. I think there's a nice mix of skills in there which allows us to have a top seven to build big totals and equally we've seen how the lower order can then be entertaining as well. If you build the platform, anything can happen."

Dom Bess, Sibley and Crawley, three players who have been important parts of England's victory, will join up with the Lions for their three-match red-ball tour to Australia next month as originally planned. The ECB hope it will allow them to gain experience of playing in Australian conditions as well as providing the trio with opportunities to play red-ball cricket in the lead-up to the Sri Lanka tour. They will leave with the rest of the squad on February 7.