A clinical 54-0 dismantling of the Sharks in Durban on Tuesday has sharpened competition for places in New Zealand's first Test XV, with coach Dave Rennie satisfied despite noting his side still have significant room for improvement ahead of the August 22 opener against the Springboks.

The All Blacks ran in eight unanswered tries at King's Park in wet, heavy conditions, a marked improvement on their unconvincing 38-21 win over the Stormers in Cape Town on Friday. Winger Fehi Fineanganofo crossed twice, with Damian McKenzie, Caleb Clarke, Jordie Barrett, Kyle Preston, Timoci Tavatavanawai and lock Sam Darry adding one each. Ruben Love converted seven.

The Sharks, fielding a youthful side with no internationals available, showed early resistance before Fineanganofo broke through on the short side in the 19th minute. McKenzie added a second before halftime before going off injured at the break. The second half was one-way traffic, with the visitors' pace out wide repeatedly exposing a tiring home defence.

Rennie acknowledged his side's slow starts remain a concern. "We can't afford to start games like we have in the two games here," he said. "In the first 40 minutes, we gave away a lot of penalties early and just didn't build enough pressure for long enough. But the second half was excellent — we kicked really well, a lot more clinically, and continued to defend well."

With Rennie committed to giving all 44 touring squad members game time across the first three provincial fixtures, the depth of competition for Test spots is becoming a live issue. "We've got a lot more people who have got good time and so there's a really good competition for spots, and that's really important heading into the Tests," he said.

The evening's talking point away from the scoreline was the appearance of 44-year-old Ma'a Nonu, who joined the Sharks recently in a leadership and mentorship role. Nonu, a 103-cap All Black, performed a solo response to New Zealand's pre-match haka before delivering several trademark tackles in a 20-minute cameo that drew a strong reaction from the 14,759 at King's Park.

New Zealand face the Bulls in Pretoria on Saturday in their third provincial match of the tour.