When Mohammad Irfan left the field two balls into his fourth spell, Pakistan were already playing with limited bowling options. With only a pair of specialist seamers and spinners each, without him, Pakistan were down to three bowlers, and when he walked off, it seemed that could cause some problems.

Hashim Amla and JP Duminy were playing fluently, and with barely any turn on a deck that was flattening out, Pakistan seemed to be in for the long haul. They had already shown their reluctance to use Younis Khan's medium-pace when Zulfiqur Babar was brought on as first-change in the 10th over. The left-arm spinner's first spell was placid, as he tossed it up generously and offered some relief from one end.

Despite that, they managed to put the world's top-ranked team in a precarious position using only four bowlers, thanks largely to the efforts of Junaid Khan upfront, and the spinners later on. Junaid opened with a four-over spell and obtained significant movement to make Graeme Smith's stay at the crease uncomfortable. After a four-over break, he returned for another, beating Hashim Amla's bat on occasion, and getting the crucial wicket of Jacques Kallis with what was probably his delivery of the day - one which bent back in and took the inside edge.

But with the older ball, the South Africans found him easier to play, and that may have been where Pakistan missed a third seam-bowling option. Their lack of a pace-bowling all-rounder seems to offset the balance of their team and they will have to rely heavily on the spinners to make up for that.

The early signs suggest they can. Saeed Ajmal's stamina meant he could easily operate from one end all day once he was brought on, and it seemed that would be the case when he came on before lunch. He bowled non-stop from the 22nd over till tea, making it 17 overs on the trot.

Although he was fairly unthreatening in that time, the South Africans treated him with the respect his reputation has earned, and having him as a constant allowed Misbah-ul-Haq to rotate the rest of the bowlers from the other end. That may be the way Ajmal is used in the early exchanges between these two sides, as a slow poison of sorts to create frustration and allow things to happen at the other end before striking himself.

An example of that came when the man stationed in an unconventional position behind square leg for JP Duminy's sweep shot gave Babar his first Test wicket. And then things started to turn for the spinners, with Babar and Ajmal taking advantage. With South Africa at 222 for 8, they could have finished them off for under 250, but it was perhaps the lack of an additional bowler which made it difficult for them to achieve that.

Misbah will probably have to call on Younis at some stage, but will be relieved that Irfan was able to get back on to take the second new ball. The tall man later confirmed it was nothing more than a case of cramp, exacerbated by slight dehydration, and that he felt better after increasing his water intake. He confirmed he would be able to play a part in the rest of the match but predicted he may not be the danger man.

"At the end of the day, the spinners dominated," Irfan said. "Although it is not turning that much, our spinners are still getting something out of it, and will hopefully have more in the second innings."

Pakistan would have thought they were in a similar position of advantage after they bowled South Africa out for 253 in their first innings at the Wanderers in February. That was the first, and only time, in the home summer that South Africa were challenged, and that too in conditions tailor-made for their pace attack. All Pakistan could muster in response was 49 all out, thanks to a Dale Steyn special of 6 for 8 in 8.1 overs.

Nothing as emphatic should be expected tomorrow, given the conditions, but Duminy hinted the seamers are already smarting on behalf of their batsmen and will want to make up for a day which they "definitely" felt they ended "behind" on. "Having the bowling line-up that we do, you've got to back us to do a great job," Duminy said.

Firdose Moonda is ESPNcricinfo's South Africa correspondent