PRETORIA, SOUTH AFRICA - FEBRUARY 14: Mitchell Johnson of Australia during day 3 of the 1st Test match between South Africa and Australia at SuperSport Park on February 14, 2014 in Pretoria, South Africa. (Photo by Lee Warren/Gallo Images)

Johannesburg – After claiming match figures 12 for 127 in the first Test against South Africa, Australia's left-arm speedster Mitchell Johnson reckons he can still improve.

“I said to Michael Clarke after the first innings that there was definitely room for improvement in that second innings,” Johnson said after his side's comprehensive 281-run Test victory in Pretoria on Saturday.

“You are always trying to improve as a player and trying to always get better and that's what I'm going to try and do throughout the series.

“Playing away from home is where you can really test yourself and we are up against the number one side so it is good motivation for us to just keep getting better. I don't think you ever play a perfect game, but it felt pretty good at this stage.”

Johnson took 7/68 in the first innings to help bowl South Africa out for 206, and then followed up with 5/59, dismissing the hosts for 200.

Johnson's match figures of 12 for 127 bettered his previous match best of 11 for 159, also against South Africa, in Perth in 2008/09.

“When you can get wickets like that against great opposition, it is very exciting and it does make you proud inside,” Johnson said.

“I guess for me it will be something I can look back on when I finish my career and be really proud of that moment. For now, I just really want to improve with only one Test match gone and two to come.”

The constant yearning for improvement was part of the Australian team philosophy, Johnson said.

“We said it throughout the summer back home - we want to get better as a team and for me personally I want to keep that consistency going and just keep that pace up.

“We bowled well as a bowling attack today and we stopped them in their tracks.” – Sapa