Duanne Olivier had one job: to do the same thing he did last summer.

Except that he did it against an international batting line-up not a local one, with one of the most promising young bowlers on the global circuit at the other end, Kagiso Rabada, not his franchise partner Marchant de Lange, in front of a small but vociferous crowd, not an empty ground. So even though this one job was the same job as the one Olivier had always done, it had become a much harder job because it had been added to by expectation.

Olivier was last season's leading wicket-taker in first-class cricket with 52 scalps, some distance ahead of his nearest competitors, who had 34. It was widely understood that he was a wicket-taker but because the competition is not televised, very few people had actually seen what kind of a wicket-taker he was. Word around the game was that he had a decent short ball but also that he had the stamina to return for spell after spell and the ability to be effective with the older ball.

But all of this was just talk. None of it had been seen at international level because Olivier had not had that much opportunity to show it.

He debuted against a mentally shot Sri Lankan side that made for easy-pickings, was inconsistent in England in a series South Africa want to forget and was unspectacular in Potchefstroom last week when Morne Morkel set the tone. Here on his home turf, with all but one big name - Rabada - unavailable, he had his chance to prove what he is capable of and Faf du Plessis was particularly pleased with the outcome.

"That's what you want to see from young bowlers. You want to see improvement, that they can learn quickly at the highest level, because the guys that can learn, you can stick with them," du Plessis said. "The way he bowled today was a fantastic effort. To bowl 10 overs on the trot of short-ball work takes incredible effort, so I have to take my hat off to him. He was our best bowler today."

Olivier's spell started on the second evening when Bangladesh followed-on but he really got into his work on the third morning when, for the first time, he appeared to be bowling to a plan. South Africa had a short-leg in place and Olivier was told to pitch it short. His sixth ball climbed on Soumya Sarkar and carried to Aiden Markram under the helmet but he could not hold on. Later in the over, Olivier bounced Sarkar and then aimed at his ribs. In the next over, Sarkar prodded at one from Rabada and was caught at second slip.

Then, Olivier turned it up. Men were sent out on the leg side waiting for the hook and Olivier ramped up the pace and the effort. Imrul Kayes almost gloved one as it sailed past his hips and Mominul Haque had one hurtle towards his face. Olivier set them up so Rabada could take them down. Mominul holed out to deep square leg off Rabada in the ninth over.

Bangladesh's captain Mushfiqur Rahim bore the brunt of Olivier's aggression and there were many hearts in mouths when he was hit on the helmet and required treatment. Olivier, not shirking from his plan, delivered a short ball as soon as Mushfiqur was ready to go again.

For all the work he put in, Olivier's only reward was the strangling of Kayes down the leg side but in his 10-over spell he showed all the ingredients South Africans like to see in their quicks. He was fast and he was fiery and though there is still work to be done for him to challenge the currently-injured elites for a more regular place in the Test XI, du Plessis is now confident Olivier could get to that level.

"You can't compare any of our bowlers to KG's skill, but what we needed from a bowling attack today, we needed to be ruthless and aggressive and try and make it uncomfortable for Bangladesh, and he led from that aspect. I'm very proud that he can make those improvements," du Plessis said.

"There is a difference in our top four seamers, they are world class, best-in-the-world kind of bowlers. So if you judge guys according to them, there would be a gap. For me it is important to see how we can make those guys get better for the time when they need to step up into the team. These guys that played the last two Test matches will be looked at for the future so it's important for them to see that there is some work to do, but they have the quality."

That q-word (not quota, though there is that one too) is something of a talking point in South African cricket because there are serious concerns about their depth. To have learnt that they still have a lot of quality was an important goal in this series and du Plessis can now look forward to the rest of the summer with optimism.

"We had really good targets leading into this series of what we wanted to achieve as a team and we achieved those goals hands down, so we'll take confidence as we move into two big series," he said. "We appreciate that India and Australia are going to be a lot tougher. Bangladesh didn't have the firepower we thought they would have in these conditions. We won't get too far ahead of ourselves in thinking we are the finished article."

Firdose Moonda is ESPNcricinfo's South Africa correspondent