SYDNEY - Destructive centres Sonny Bill Williams and Ma'a Nonu collide in a much-anticipated World Cup selection trial as Super Rugby leaders Wellington Hurricanes test their title claims against the Waikato Chiefs this weekend.
Central Cheetahs' Jean Cook (R) tackles Waikato Chiefs' Sonny Bill Williams during their Super 15 rugby union match, at Waikato Stadium in Hamilton, on March 28, 2015
It is an intriguing sub-plot to a massive game in Wellington on Saturday as the Hurricanes seek to extend their 10-point lead over the twice champion Chiefs in the New Zealand conference.
Williams and Chiefs midfield partner Charlie Ngatai will be up against the Hurricanes' regular Test pair of Nonu and Conrad Smith, who are the centrepiece of an in-form backline for Wellington, who have lost only once in 11 games this season.
The match will be the 50th as a midfield pair for skipper Smith and Nonu and how Williams fares will be watched closely by the All Blacks selectors.
"We've seen some clips and they've just been splitting teams open, so if we can combat that I think we'll do pretty well," Maori All Blacks captain Ngatai said.
"Me and Sonny have worked pretty much the whole season together. It's working well for us and we're feeding off each other."
Last year the Chiefs were hammered 45-8 by the Hurricanes in Wellington, and coach Dave Rennie is in no doubt about the importance of this weekend's match.
"Really it's a massive game for both sides," he said.
"If they win they seal the conference and if we win we can haul them back in and it makes for a pretty good finish.
"It's certainly a game that a lot of people have been salivating about for a long time."
James Marshall, standing in for the injured Beauden Barrett, will start at fly-half, while winger Julian Savea and scrum-half TJ Perenara return for the big game.
- 'Great momentum' -
The Northern Bulls get the chance to leapfrog the inactive Western Stormers to the top of the South African conference if they beat the lowly Blues in Auckland on Friday.
Bulls captain Pierre Spies is back at No.8 for Arno Botha at the back of the scrum. Botha will move to the side of the scrum, with Jacques du Plessis on the bench.
"At this stage of the competition you need to be playing your best rugby and have great momentum," coach Frans Ludeke said.
"We are pretty close to that and we cannot afford to slip up if we want to stay in the play-off race. We are playing a very dangerous team so will have to execute very well."
It is tight as well in the Australian conference with the ACT Brumbies, one-point leaders over the New South Waratahs, facing a testing game against the Golden Lions in Johannesburg after last week's heartbreaking 25-24 defeat to the Stormers.
Wallabies playmaker Matt Toomua has been rushed to South Africa to join the touring Brumbies after recovering from an ankle injury during which time they have lost their last two games.
"It's hard to watch (when the team is losing), a positive is that I'm back and I've got a few games to play well to hopefully assist getting our season back on track a bit," Toomua said.
The NSW Waratahs will be without destructive back-rower Jacques Potgieter, who has a chest injury, for Saturday night's clash with South Africa's Coastal Sharks in Sydney.
In this weekend's other games, the troubled Queensland Reds host the Melbourne Rebels, and the Central Cheetahs face the Otago Highlanders in Bloemfontein.
The Canterbury Crusaders, Western Force and Stormers have byes.