Mark Wood told Joe Root he was ready to "charge in one more time" and fill the void left by Jofra Archer for England in the fourth and final Test with South Africa.

Wood was instrumental in England taking control of the series finale on day two in Johannesburg, hitting an unbeaten 35 as part of an 82-run stand with Stuart Broad - the highest 10th-wicket partnership at the Wanderers - to push the tourists to 400, before taking 3-21 with the ball as South Africa slumped to 88-6 in reply.

The seamer was not even going to play in the match, but more elbow issues for Archer meant Wood was included after making his case to Root.

"Probably until the morning of game I wasn't in the team," Wood told a media conference.

"Jofra was definitely going to play, two days out he looked really good in the nets, and it was probably me who was going to miss out because I was just stiff and sore everywhere.

"Then it was a role reversal, on the morning of the game he was still feeling his elbow and I felt good enough to play.

"I spoke to the captain and coach and said, 'If you want me, I'm ready to go.' I felt good in the warm-ups and I said, 'I'm not quite sure how it's going to go but I'm ready to charge in for you one more time.'

"I couldn't guarantee them I could bowl 90 miles per hour in my fourth and fifth spell but I'm glad I made that decision and it's going well."

Wood and Broad took the fight to the South Africa attack after England had slipped to 318-9. Broad struck four sixes and Wood three in a confidence-sapping spell for the hosts.

"I did a lot of work behind the scenes at Newcastle's indoor centre. Sometimes with my dad Derek, sometimes with my wife Sarah, just feeding me the balls on the bowling machine," Wood explained when asked how he has managed to adapt to the pace and bounce of surfaces in South Africa.

"My wife would be laughing telling me to get in line, she got me a couple of times. My dad is particularly spicy as well. The worst is [head coach] Chris Silverwood, though, because he laughs when he hits you.

"You'd think the coach would be more supportive, but he's still got a fast bowler in him I think."

South Africa will resume on day three with just four wickets in hand and needing another 113 to avoid following on as they did in the third Test.

Quinton de Kock was unbeaten on 32 with Dwaine Pretorius the new man to come in after Anrich Nortje was dismissed with the final ball of day two.