Allan Donald has described South Africa's bowling line-up as the best he has seen as the world's top-ranked team prepare to seal a sixth successive Test series win in Cape Town this week.

The Proteas hold a 1-0 advantage in the three-Test series against Pakistan after ripping out the tourists for just 49 in Johannesburg a fortnight ago.

It was not the first time in recent history that South Africa's attack has embarrassed their opposition after skittling New Zealand for 45 last month while Australia managed just 47 last summer.

Worryingly for Pakistan, both of those low scores were recorded at this week's venue.

It is hardly surprising then that South Africa's bowlers have been credited as the major force behind the country's rise to the top of the Test standings.

Bowling coach Donald, who could be surpassed by Dale Steyn as the country's third-highest Test wicket-taker this week, believes they deserve even more credit than that.

"The current crop of bowlers is definitely the best I've seen," Donald, who took 330 Test wickets, told reporters.

"Collectively, when there is a change of bowler, the pressure never stops. The heat is relentless from both ends and the pace is relentless from both ends, and I think that is a big accolade for this group of bowlers.

"We have to make sure that we stay relentless in our approach, but it's fantastic to work with this group of players."

However, Donald has warned his quicks they could be forced to graft in Cape Town after recent hot weather has baked the Newlands surface dry.

That could open the way for Pakistan's spinners, led by Saeed Ajmal, to take control as the match wears on and opener Alviro Petersen is wary of their threat.

"It's not quite a 49 all out pitch," he said.

"If there is one ground where they can bounce back it's Newlands."

If the pitch is to prove benign early on Petersen knows the onus will shift to him and his fellow batsmen to perform.

"Our bowling unit absolutely deserves all the hype they're getting at the moment," he said.

"There is pressure on us batsmen too, because we must also perform.

The Proteas batsman are likely to face a unique test with Pakistan likely to draft in giant quick Mohammad Irfan for his debut. At 7'1" Irfan would be the tallest player to play Test cricket.

"We were all surprised when Irfan wasn't selected for the first Test because he offers something different," Petersen said.

"We've done our homework on him and he's the type of bowler we've never faced in our lives.

"I'm sure he'll play in the second Test so we will have to prepare well for him and try and find a way or come up with a technique to play him."

Pakistan captain Misbah-ul-Haq is confident his side can bounce back, but rubbished suggestions they would reinforce their batting line-up after the opening-Test capitulation.

"Wherever you go in the world, six batsmen and a wicketkeeper have to take responsibility," he said.

"We are improving, in terms of batting and in terms of attitude.

"I am really confident that these guys can fight back. Whenever we've had tough times, we have been able to come out of it."