AB de Villiers described his appointment as captain of South Africa's Test team as the fulfilment of a life-long dream but it will raise further questions about the burden on the team's outstanding player.
De Villiers was handed the captaincy following Hashim Amla's decision to stand down after the drawn second Test against England on Wednesday.
"I've said this before that it is an incredible honour to captain South Africa in any format. The captaincy has obviously come at short notice and is the realisation of a lifelong dream," De Villiers, already South Africa's one-day international captain, said in a statement.
De Villiers, who turns 32 next month, will lead South Africa into the last two tests against England, starting next week in Johannesburg, and is favourite to get the job long-term, coach Russell Domingo said.
That, however, will only rekindle the debate over the workload on one of the world's most talented batsmen, who plays an important role for his country in all formats of the game.
De Villiers was last week forced to deny newspaper reports he was ready to quit the test arena to better balance time with his young family and cricketing commitments, which also include playing in the lucrative Indian Premier League.
He played as wicketkeeper in the first Test against England in Durban, which South Africa lost by 241 runs, in order to allow the selectors to pick an extra batsmen but after a poor performance he quickly gave back the gloves.
Cricket South Africa said it would look at ways to give him time off but have now thrust a new responsibility on to his shoulders.
"At the moment my priority and focus is placed on leading this team to what can be a memorable series win against England,” De Villiers said.
"This Test squad is motivated and determined to turn our performances around and I'm looking forward to taking up that challenge as captain. Hashim is a good friend and close colleague and I am grateful for his support."
Amla sprung a surprise with his decision, which came just one day after he scored 201 to help drag his team back from the cusp of losing a second successive Test to England.
He said he felt there were better candidates to lead the team and wanted to concentrate on his batting.