All Black sensation Sonny Bill Williams reckons he's still "a work in progress" despite his starring role in a 49-3 rout of Scotland at Murrayfield.

New Zealand scored seven tries, several created by rugby league convert Williams's brilliant skill in slipping the ball out of the back of his hand.

In an era where much of the talk in both codes of rugby has been about players' physical prowess -- and at 6ft 3in (1.91m) and 17 stones (108kg) Williams's vital statistics are impressive -- the centre's display was a reminder there is still a place for a midfielder who knows how to time a pass.

Such was the commanding nature of Williams's display, and the way his team-mates were on the same wavelength, it was easy to forget that Saturday's match was only his second Test in rugby union.

But he has now played a major role in helping New Zealand be halfway to what would be a third 'grand slam' in five years following their 2005 and 2008 clean sweeps of the 'Home Nations', with Ireland looking to stem the All Black tide in Dublin this coming weekend ahead of the tour finale against Wales.

Not that the 25-year-old Williams, who played alongside England fly-half hero Jonny Wilkinson at French club Toulon before heading home, was getting carried away.

"There's still things I need to address and work on, but I've always said I'm a work in progress," Williams insisted. "I've got to keep on working and continue to improve.