London: AB de Villiers has vowed to end his barren run in the nick of time as the South Africa captain prepares for a must-win Champions Trophy showdown with India.

After two disappointing performances with bat, De Villiers is under pressure to save South Africa from elimination in their final Group B match at The Oval on Sunday.

The 33-year-old's first golden duck in his long and successful ODI career came during South Africa's shock 19-run loss to Pakistan at Edgbaston on Wednesday.

De Villiers has managed just four runs in the tournament, but the right-hander, who declared himself fully fit after recent hamstring problems, is convinced he will get back on track against India.

"Look, I'm still in good form. Still hitting the ball well, as always," De Villiers told a press conference on Saturday.

"It's just a matter of going out and doing it. There's nothing I can say here that's going to change anything except for that I still believe I can and hopefully I'll prove that tomorrow.

"But I'm very excited with this opportunity for the team and for myself on the big stage to go and just enjoy what we do best.

"We're very excited about tomorrow and I also feel really excited about the opportunities."

With both India and South Africa having taken one win from their two group fixtures, De Villiers' side must beat the holders to reach the semi-finals.

South Africa haven't made the Champions Trophy final since winning the inaugural edition in 1998, but De Villiers expects his players to produce a dominant display, as long as they keep calm.

- Big stage -

"It is a must-win game, but we've played quite a few of them in the last 12 to 18 months and we've had a lot of success in those must-win games," he said.

"The guys generally perform better if they are relaxed in their mind sets and not too tense. That's partly my responsibility to make sure there's no panic.

"It's really important to stay calm. Not get over-excited. The tendency will be there, because we all live for these kinds of moments. 

"That's why we play cricket, we want to play on the big stage against the big teams and tomorrow is one of those games."

For some of De Villiers' harsher critics, the India showdown will also serve as a referendum on his captaincy.

But the Pretoria-born star insists he doesn't care what the doubters say about him.

"I think my captaincy is pretty good. I've thoroughly enjoyed every second out there," he said.

"Lost the last game, so that's never ideal for a captain. I understand what I'm trying to do out there. I'm really enjoying the captaincy. 

"I think I make some good calls. But yeah, pencil's in your hand, and I unfortunately can't control what you're going to write but in my mind I'm a good captain. 

"That's unfortunately going to come down to the result again tomorrow. Hopefully it's a good win."