When Morne Morkel found success in the final Test match against New Zealand in March, he did more than become the only South African to take the first six wickets in an innings. He outbowled Vernon Philander and Dale Steyn.

It was something Morkel had not done in the six matches before that, since Philander had been given the new ball ahead of him. He found a confidence he had not had before, an aggression that was usually hidden and an intensity that he did not seem able to sustain in the past.

Even when Morkel was part of what was being labelled as the world's best opening pair, it was Steyn who did put fear into the hearts of batsmen intentionally, using swing, pace and a bullying glare. Morkel had the ability to hurt them and sometimes he did, but he never tried to do that with anything other than the ball. There were no clever, or even not so clever, quips, no piercing stares that cut through a batsman's confidence and no over-heating to approach combustion, the way a typical fast bowler fumes.

Recently, that has changed. Since his six-wicket haul in Wellington, Morkel's mean streak has become a little longer and according to the bowling coach, Allan Donald, it's going to keep growing. "He has gone a little bit further in terms of his personal development," Donald said. "He has found something else, he has found a bit more of that mongrel that we talk about. I think he has overstepped the line in terms of finding someone who wants to engage in battle a little bit more"

Morkel started the tour of England as badly as a bowler can. Peter Trego hit him for six fours in the first over he bowled in Taunton. Instead of spit fire, Morkel congratulated the batsman when he walked up to him at the end of the over and gave him a friendly pat on the shoulder. He went on to concede 90 runs from his 14 overs and sprayed the ball both sides of the wicket, usually a sign that a rough patch lies ahead.

This time, though, he was able to turn that around quickly. Morkel was the one who made major incisions in Canterbury, where he enjoyed a much better and more controlled return. He was the standout bowler from the first day of The Oval Test, where he was given the new ball because of what Steyn called a "psychological edge," over Andrew Strauss who he promptly dismissed fourth ball and was the most economical bowler at New Road where he also picked up two wickers.

The steady progression of his form as the tour has gone on has been one of the clearest hints of consistency Morkel has ever given. Combined with a new found hostility, it seems Morkel is ready to take the next step.

"He is a confidence bowler, there is no question about that," Donald said. "The more he bowls, the better he bowls. He's got great confidence right now and he is in a good place. We are fine-tuning things all the time and I am not going to be pushy about that. He is learning all the time and he is starting to show us what lies on the other side of Morne Morkel."

To bring out that other side, Donald made sure that neither Morkel, nor any of the rest of the Test attack, were rested for the tour match, a move that was in complete contrast to England. None of their bowlers who played the first Test appeared in the county matches before Headingley while South Africa's pack were all put through at least three spells at New Road.

"It's easy to say Dale or Morne should have a rest but I think momentum is a big thing, not only as a team but for the bowling group," Donald said. "It's important that we tick over, and get a few overs under the belt, not as much as in a Test match but just for a bit of confidence. When you are on a tour you always look for that confidence and form and we want to maintain that."

Maintenance seems a simple task for South Africa's bowlers, especially considering that they managed to take 20 wickets on a surface which England's attack could only snaffle two but Donald said there are areas of concern he highlighted to them. "We want to get out of the blocks better," he said. "It's not that we bowled poorly on the first day at The Oval but we want to have a real solid start with the ball."

Donald believes South Africa "bowled themselves into a winning position," on the second morning last week when they dismissed England for 385. While taking nothing away from the batsmen who put in a performance "you may never see again," he said the bowling onslaught, driven by the need to up the intensity, was crucial to giving South Africa the lead.

Now that they have that advantage, Donald said the approach would be not to sit on it, but to press it home. "There's no ways we are going to sit back and wait for things to happen. We know what's coming our way and we know England will throw everything at us," he said. "We take nothing for granted. We've won a Test match but we haven't won the series."