Murphy and his co-driver, fellow Supercars pilot Jack Perkins, put on a dominant display to take the lion's share of the points and close the gap on series leader John McIntyre.
However, one of the new generation of V8 drivers, Scott McLaughlin (with Jonathon Webb), has been the man to beat since missing the Manfeild round and leads the championship heading into today's first race.
The 19-year-old has been turning heads in Australia in the V8 Supercars' development series, which he leads after Winton with one round to go. He really made folk take notice when he finished sixth at the Bathurst 1000 co-driving with Webb.
The duo were on song at Pukekohe, winning the opening race on the Saturday, and were the only pair to take it to Murphy and Perkins all weekend, finishing with a first and two seconds. McLaughlin, who has a 155-point advantage over McIntyre, is set to battle it out with his boyhood hero again at the Canterbury circuit.
"Manfeild was a low point for us but we've put our heads down and showed everyone what we can do," said McLaughlin. "I've had a few good races that have got us back in contention for the title."
He is nicely set up to win the overall title and has a fair chance to get one over Murphy and grab the endurance title too.
Former NZ V8 champion John McIntyre has, by his standards, had a fraught time since winning the sprint title as part of the overall championship and is sandwiched between his two transtasman rivals.
What makes matters more difficult than going head-to-head with two on-form drivers is that McIntyre (driving with Jono Lester) has to drop his points from a round - as all drivers do. The bad news, though, is that Murphy and McLaughlin have rounds to drop where they scored no points anyway.
"We need to get all 900 points on offer over the weekend and the others [Murphy and McLaughlin] to get none if we're in with any chance of winning the championship," McIntyre said.
"It'll be a hard ask as the others have been doing a better job than us, there's no doubt about it. Getting a couple of wins would make it a great weekend for us and then let the points sort themselves out.
"It's been the toughest series we've ever raced in New Zealand by a long stretch. It's really down to us, Andy [Booth] and Jonny [Reid] for third place in the series.
"Ruapuna's the scene of our only win this year so we just have to sharpen the car up in qualifying and take it from there."
Another driver mathematically in contention for the title in the Driven-sponsored International Motorsport car is Jonny Reid, who's fourth in the series. But he's in the same boat as McIntyre and will lose points as well when he drops a round.
"The memory of my two-race haul at Feilding is still fresh in my mind and it's that spark I'll will be looking to re-ignite this weekend," said Reid.
"Now, obviously, it is quite a challenge [to win the inaugural V8 SuperTourers NZ title], but we're still in the hunt and while we are I can guarantee that I will be putting absolutely everything into it until I see that final chequered flag."
There have been 15 races over six rounds in the run-up to this weekend. McLaughlin and Murphy have five wins each and Murphy's car has another two when in the hands of Fabian Coulthard at the sprint round at Ruapuna. McLaughlin didn't have the best of events last time the cars were down south, only managing a fifth, a DNF and a seventh.
Both two-driver 53-lap endurance races will run on Sunday with qualifying on Saturday.
Points after six rounds
Scott McLaughlin 2995
John McIntyre 2840
Greg Murphy 2732
Jonny Reid 2654
Andy Booth 2308
Kayne Scott 2299