Mitchell Johnson is used to being quick, though usually it's the speed of his bowling that attracts the most attention. On the fourth day at Seddon Park he did break the 150kph mark on a regular basis to drive Australia closer to victory, but of equal interest was how fast he reached a milestone. When Johnson rattled the stumps of Tim McIntosh, it was his 150th wicket in 34 Tests, fewer games than any other left-armer in history took to reach that landmark.

Only eight left-arm pace bowlers have got there, and that includes Garry Sobers and Bill Johnston, who switched between seam and spin. At the head of the field is Wasim Akram, and after Johnson was told of his achievement he said he was thrilled to be in the same company as Akram, who took 41 Tests to get 150 wickets.

"I used to watch him when I was younger and I guess you grow up and want to be able to do the things that guys like him did when they played," Johnson said. "I used to watch the lefties when they were around, like Bruce Reid, and one day you hope you have the chance to do that. All us lefties do stick together I suppose."

Perhaps a greater compliment than the record came with the word of the opposing coach Mark Greatbatch, who watched on in dismay as Johnson skittled three of New Zealand's top four batsmen with his speed, angle and unpredictability. Only Waqar Younis dismissed Greatbatch more times in international cricket than Wasim, whose key weapons were accuracy and swing.

"He's not the same left-armer as Akram but he looks like he can go up two or three gears on a flat deck, which is a real skill," Greatbatch said. "He has that energy and that ability. It's slightly different the way he did it as what Akram did it but it's still the same quality."

The ball that beat McIntosh was 150kph and the first delivery that Mathew Sinclair faced was even quicker at 152kph. Johnson was keen to use the variable bounce in the Seddon Park pitch to unsettle the batsmen, pushing McIntosh back with a leg gully to get him thinking of a short ball, and he also kept one eye on the radar gun.

"I think most fast bowlers do, you want to see where you are at," Johnson said. "It felt good for me rhythm wise, the guys behind the stumps were encouraging as well, saying it was going through well. You always have a glance now and then. If you think you have bowled a quick ball, you have a look up. It's nice to see when the ball is over 150, I don't mind seeing that at all."

The batsmen didn't like seeing it. After McIntosh, Johnson drew edges behind from the right-handers BJ Watling and Ross Taylor and put Australia in a strong position to aim for victory on the fifth morning. If Johnson has his way, the result will come quickly.

Brydon Coverdale is a staff writer at Cricinfo