New Zealand v South Africa, 2nd Test, Hamilton, 1st day March 15, 2012

Steyn and Philander shatter New Zealand

New Zealand appeared to be well placed at 133 for 2 but Dale Steyn and Vernon Philander combined brilliantly to rip out the heart of the home side

To change the complexion of an innings in four overs takes a bowling effort that is ruthless, relentless and is able to, as Iain O'Brien put it his tweet, get "one sniff of blood in the water and it's feasting time." Over the space of 20 deliveries, Dale Steyn and Vernon Philander fit that description perfectly. The pair comprehensively derailed a New Zealand train that was chugging along at a comfortable pace and created a passage of play that could end up being one of the most significant in the context of the series.

When Steyn and Philander are both at their best, they create a cauldron of pressure that can suffocate the batsmen with the best technique and temperament in the game. Those that do not have the best of either, have very little chance.

Steyn had started within himself, bowling in the mid 130s and although he got swing from the outset, his bowling lacked venom. Some thought it was due to his ragged toe that became a television celebrity while others blamed his usual need to find his rhythm first. Steyn insists it was neither.

He appeared visibly annoyed that his toe has been the recipient of such fame. "There's actually nothing wrong with it. It's a fast bowler's toe," he said. "If you go and look at Morne Morkel's toe, they probably look worse than mine. This was one was just a little bit of a blood." True to his word, when he displayed his toe to the media who could see it, there weren't any signs that something was wrong.

As far as his rhythm was concerned, Steyn said he felt he had hit the right notes as far back as the one-day series. "I just haven't found the edge," he said. "I bowled nicely in the one-day games, and thought I bowled okay in the [first] Test match on a wicket that probably didn't suit the quickies."

Despite Steyn's protestations, the question was still being asked: why isn't he at his best? He felt that he always was but hinted that something extra clicked in this innings. "I know that I am bowling really well when I am bowling really quickly." And that is the difference. For the first time on this tour, Steyn cranked up the pace to the mid 140s and stayed there. He got the ball to move into as well as away from the right-hander - the away movement accounting for the scalp of Martin Guptill, who hung his bat out to the second ball of Steyn's second spell.

By his third one, Steyn's pace was back be and the snorter he presented to McCullum was a sign of things to come. It was a short ball that McCullum had to arch his back to watch as it zipped past his helmet. In the fourth one, the trap had been laid. McCullum had got to 50 and was pulling with confidence so a deep square was sent to the boundary and Steyn peppered him with short balls. It took just five of them for McCullum to take the bait and start a dramatic collapse.

Only three times in Test cricket has a team lost five wickets without adding to the score and all three times that team has been New Zealand. Steyn prised open the defences and Philander reached in and pulled the guts right out. His stuck to his usual line in the channel outside off and had Ross Taylor caught at slip. Steyn stuck with a brutish short ball at the other end to account for Kane Williamson before Philander's seam movement completed the carnage. Together, they left New Zealand in shreds.

What was different about their destruction in this match was that they did it with the old ball as Philander found reverse swing. He complemented Steyn's out-and-out pace, adding a new shade to their already colourful palette. "Bowling with Vernon is probably the same as bowling with any other guy but probably a little more exciting because he brings the ball back in," Steyn said. "With Morne [Morkel] or Marchant [de Lange], it's probably a bit more one-dimensional. But with Vernon, there's always something happening."

Philander's consistency has pushed Steyn into the shadows in recent times and has forced him to play a different role, which involves doing a containing job when needed. "I have to go through phases where on these pitches where the ball is not going to be pinging through and [Mark] Boucher is not going to be catching every ball above shoulder height from a length. There's spells when you really have to dry things up and you've got to work with who is bowling on the other side and think, 'Who's more dangerous right now?' On most days, it seems like Vernon is the guy that's most dangerous."

Philander will not always be the chief assassin but on the slower tracks of New Zealand the threat he poses is more pronounced. The secret to making the most of that threat is to have Steyn on the other side, offering a different challenge to batsmen. Graeme Smith, in bringing Philander back on once Steyn had "put my foot down a bit and opened the door," showed that he knows how to make sure that door gets shut as well.

Firdose Moonda is ESPNcricinfo's South Africa correspondent