He has been in possession of the job since long-time gloveman Mark Boucher suffered his career-ending eye injury in England last year.
There are those who maintain the country's best wicketkeeper is Thami Tsolekile of the Johannesburg-based Lions.
But de Villiers, a cracking fielder and no slouch behind the stumps, enables South Africa to play an extra batsman at No7, or, potentially, strengthen the bowling.
So the challenge is to prove he is the man for the job.
"I'm really enjoying my role as wicketkeeper-batsman in the top order and want to be wicketkeeper for many years," de Villiers said.
"But I know I have to really perform well and improve my keeping and batting all the time."
De Villiers used to keep wicket as a 9-year-old but when he ascended to the national team, Boucher was a significant obstacle.
De Villiers is the highest-positioned wicketkeeper in the test game.
England's Matt Prior is often No 6; New Zealand's BJ Watling is filling that role now.
Australia, India and Sri Lanka all have their No7 spot occupied by the wicketkeeper.
But none of them have de Villiers' batting proficiency. Most recently he belted Australia for a run-a-ball 169 to help set up the series-winning victory in Perth, which kept them top of the world rankings.
That was testimony to his aggression and skill at the crease and an ample demonstration of why he's ranked the world's seventh test batsman and second in the ODI game behind Amla.
There is a complication, however, which may in time make keeping a second string too much for de Villiers.
He has had back problems - soreness and stiffness - which he insists is manageable.
"I have worked really hard with our physio and it's a self-responsibility to make sure I am as fit as can be, looking after my core stability, stuff that helps the back to perform for a longer period."
There's nothing that can be done to fully repair the back.
"It will always be around. There's definitely not a massive alarm bell that goes off when the specialist sees the x-rays. I'll have to look after it really well."
He's relishing tonight. Fond memories remain from his debut and "I've always loved playing here".
That said, St George's hasn't been that kind as a test venue to de Villiers. All three tests he's played in Port Elizabeth have been lost - also South Africa's last three at the venue - and he's averaging 29.66 there. He's due.
AB de Villiers
Tests: 81; runs 5961, average 49.26, 14 hundreds
ODIs: 132, 5168, 49.21, 13