YOKOHAMA, Japan (AP) — The heated debate in New Zealand rugby about playing Richie Mo'unga at flyhalf instead of Beauden Barrett, and Barrett at fullback instead of Ben Smith, might cool down now.

The dual playmakers model, making a fourth appearance, was a hit for the All Blacks as they contained South Africa 23-13 to successfully open their Rugby World Cup title defense on Saturday in Yokohama.

Barrett was even named man of the match. The boots of both also helped to finish off the Springboks' resistance.

Barrett and Mo'unga played together for the first time in July against South Africa. The error-filled game didn't allow each other's skills to flourish. The result was a draw. The experiment continued through the Bledisloe Cup — a loss and a win — without being convincing. But coach Steve Hansen saw enough to persist, and rolled them out against South Africa again on Saturday.

Both players were brilliant. Their positioning was expert, seeming to know what the Springboks were going to do next. They swapped at times, as Barrett played first receiver and Mo'unga covered the backfield. Mo'unga had to make some key tackles.

Mo'unga also nailed four of his five goalkicks, and when he was replaced late, Barrett kicked the last penalty to put the All Blacks beyond reach.

"I love playing with Richie, he's a super talent," Barrett said.

"Hopefully for this team we can figure out how to get the best out of each other and do what's best for this team. We've got a lot more potential in us. It's only going to get better."

Barrett won world player of the year honors in 2016 and 2017 as the All Blacks' flyhalf. At fullback, he's growing into the position while Smith, the All Blacks fullback when they won the 2015 World Cup, is in the reserves.

"From my attitude point of view, it doesn't change whether I'm playing first five-eighths (10) or 15," he said. "Tactically, things will change; I have to vary how I do things out there. But as an influencer of the game I want to be as demanding as I can."

He's also having to adapt to playing with new wings Sevu Reece and George Bridge. Barrett offloaded for Bridge to score the opening try, and had to try and tune into the unpredictable Reece. One of Reece's highlights was a diving reverse pass to Barrett behind the tryline, while surrounded by Springboks.

"If it's a 50-50 (decision) for Sevu, he'll call it for himself and go for it, which is great," Barrett said with a smile. "We can feed off that confidence. He had moments of brilliance out there. Hopefully, we can get him more ball."

What Barrett didn't see was the try by his brother Scott, who had an easy run-in to between the posts only to finish it with an awkward half dive, as if he was worried about breaking something.

"I was already turning around heading back to halfway," Beauden said. "But it was great for the big fella to get across the line."

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