Tri-Nations: New Zealand delivered an emphatic World Cup message on Saturday with a record-breaking 52-16 win over South Africa in Johannesburg in the second round of the Tri-Nations championship.

Wingers Joe Rokocoko and Doug Howlett scored two tries each as the All Blacks confirmed their status as the southern hemisphere's leading challenger for the World Cup opening in Sydney on October 10th.

Outhalf Carlos Spencer, centre Aaron Mauger and replacement prop Keews Meeuws also crossed the Springbok line in a one-sided exhibition of handling rugby.

The score was the highest conceded by South Africa at home and their third highest anywhere.

The All Blacks's 36-point margin of victory was their largest against the Springboks, the biggest in South Africa and the second highest anywhere following England's 53-3 win at Twickenham last year.

The seven tries also equalled the most conceded by the Springboks and were the most conceded at home.

The Springboks briefly held the lead through a Louis Koen penalty but a three-try burst in 15 minutes midway through the first half tilted the game decisively in the visitors' favour.

Spencer dummied down the blindside of a ruck for the first in the 12th minute and with Howlett and Rokocoko crossing within four minutes of each other the All Blacks had sprinted into a 22-6 lead by the 27th minute.

Dominant Koen kicked his second penalty after striking a 40-metre drop goal to close the gap to 13 points at half-time but the All Blacks then utterly dominated the second period.

Spencer kicked two penalties at the start of the half before Rokocoko's second try and Meeuws's score from a lineout drive on the 66th minute killed off the Springboks' last remaining hopes at 40-9.

Meeuws was yellow-carded for elbowing Springbok replacement prop Robbie Kempson instantly after scoring the try but it made no difference to the All Blacks. They gave up a try to Ashwin Willemse in the 72nd minute but finished the stronger, scoring again through Howlett and Mauger to bring up the half-century before Meeuws had returned to the field. New Zealand coach John Mitchell attributed his team's record win over South Africa to an improved performance in the set-pieces.

New Zealand took five points from the game and lead the standings from South Africa (four) and Australia (one). They meet world champions Australia in Sydney next Saturday.

SOUTH AFRICA: B Russell (A Pretorius 56); S Terblanche, A Snyman, De Wet Barry, A Willemse; L Koen, J van der Westhuizen (C Davidson 64); L Sephaka, D Coetzee (D Santon 60), R Bands (R Kempson 54), V Matfield, B Botha (S Boome 70), C Krige (captain), W van Heerden (P Wannenburg 64), J Smith.

NEW ZEALAND: M Muliaina; D Howlett, T Umaga, A Mauger, J Rokocoko; C Spencer, S Devine (J Marshall 62); D Hewett (K Meeuws 54), K Mealamu (M Hammett 60), G Somerville, C Jack, A Williams (B Thorn 50), R Thorne (captain), R McCaw (R So'oailo 78), J Kelly.

Referee: A Rolland (Ireland).