It was as beautiful as it was brutal, and came from a place where Hamish Bond and Eric Murray knew their rivals hadn't been.

The peerless crewmates completed eight years of utter dominance in the men's pair with an emphatic repeat Olympic gold medal in Rio.

This was even more resounding than London.

LISTEN ABOVE: ERIC MURRAY TALKS TO THE CROWD GOES WILD BREAKFAST 

Both say they actually enjoyed the final 500m, a veritable coast to the line after having put five lengths on the field by the three-quarter stage.

Victory, Murray knew, was all-but inevitable if they didn't make a mistake.

He had full faith that none of their rivals had matched he and Bond's relentless training regime on Lake Karapiro since deciding in 2012 to pursue a golden double.

"If you've never been to that hurt zone, to that point of failure, you'll never think you're going to pull it out on race day," Murray told NZ Newswire.

"We were bloody nervous today be we knew we just had to live up to our own expectations and our ability. And that was it."

The pair have become a fixture at the front of their class for 24 successive regattas, a world record for a male crew.

Their winning streak stands at 69 races since joining forces after the Beijing Olympics.

They've also matched the New Zealand record achieved at those Games by another fair-haired duo, when twins Georgina and Caroline Evers-Swindell claimed back-to-back Olympic double sculling golds.

Bond and Murray's win was the opposite of the sisters' dramatic photo-finish in 2008.

Third behind South Africans Lawrence Brittain and Shaun Keeling through the opening 500m, they stayed true to a mantra that their own steady pace is one nobody can match over 2000m.

Half a boat length clear at the halfway point, the outcome was effectively sealed when clear water opened up back to their five rivals.
Murray felt the race dynamic change at that point.

"If they can't see where you are, subconsciously they're just going to be worried about winning a different medal. They don't even worry about us any more."

South Africa bagged silver, more than a length behind, holding off third-placed Italy.

Murray says they can enjoy the medal more than in London, when the over-riding emotion was relief.

"London was intense. You tried to do everything your coach told you and you didn't question anything.

"This time we've made it a little bit more enjoyable. We knew it was still going to be bloody hard and we had to make sure we were in the right mental state."

The gold is a welcome boost to the rowing squad after both men's and women's doubles crews failed to reach their final.

On Thursday, Bond's brother Alistair, was part of the lightweight men's four who slumped to a disappointing fifth in their final.

Bond hoped their triumph, as predictable as it may have seemed to many, will inject life into New Zealand's overall Rio campaign.

The rowers have a target of matching the five medals they claimed in London four years ago.

Four crews are in finals and another two in semi-finals.