Subaru rally driver, Cody Crocker, has completed a brilliant opening day at Rally New Zealand to lead the world's best Production class drivers with two days remaining.

Crocker got off to a flying start, winning the opening competitive stage, and was never headed across the remaining eight stages despite being locked in a tight tussle with fellow Subaru drivers, Toshihiro Arai and Possum Bourne.

At the end of 139.1 competitive kilometres, Crocker's lead was just 1.8 seconds over Arai, although the biggest buffer he experienced all day was just 5.4 seconds at the end of Special Stage Three.

Early on it was the three Subaru's at the top of the field, but Bourne experienced engine problems during SS5, forcing him out of the event, and it was left to Crocker and Arai to set the pace for the others to chase.

Arai closed the gap to just 0.6 seconds with two stages remaining, but Crocker took the fastest time of the Group N combatants on the penultimate stage and then held on over the final 11.64 kilometres to take the 1.8 second advantage into day two of Rally New Zealand.

But the young Victorian driver knows a huge challenge still lies ahead.

"The opening stage tomorrow is a huge test," said Crocker. "It's 59 kilometres, the longest of the entire world championship, and one that has never been that good for us, so it is vital that I get off to a good start."

"But we'll take a lot out of today. We experienced being in front and being chased when we won the opening round of the ARC in Western Australia a fortnight ago, so we'll have the same thing tomorrow. But this time it is against the best production class drivers in the world."

"I'm really enjoying it though. The car has been great again today, just like it was at the Forest Rally. We seemed to go better in the dry stages so our progress tomorrow might be a bit weather dependant."

"It was awkward out there today. The opening stage was dry, the second was wet and slippery and the third dry again. It was quite tricky with some corners really wet and slippery while much of it was perfect."

"We didn't take too many risks. We had a few small moments along the way but we never got into any real trouble.

"I've got to really dial in first up and tomorrow and get that opening stage right. It is another big day - 150 kilometres - and we do over a third of that in one stage. So after that we should have a much better idea of how we are going."

Bourne was bitterly disappointed with his early demise. It was his first outing in his new MY03 Impreza, and he had high hopes of a successful debut and collecting valuable points in his campaign for a first World Rally Championship title.

"We were just getting the hang of it when we had the problem with the engine," Bourne said.

"I'd got the suspension just the way I wanted it by the end of stage four and I said to Stace (co-driver Mark Stacey) 'come on, let's go now', but it didn't happen."

"But I've no doubt the car is a flier. I was driving within myself on the first three stages and then we went a bit harder and took some time off Cody and Arai on SS4. I know the car has a lot more potential, but sadly, I'll have to wait to the Subaru Rally of Canberra to prove it."

"Rallying can be cruel but then it makes the good times even better. There's no point in crying about it. Sometimes you have to go through a bit of pain before you go forward."

Rally New Zealand recommences at 6.43 Eastern Australian time Saturday morning.

GROUP N RESULTS - end of Leg One

1. C Crocker (Subaru Impreza WRX STi), 1hr 24mins 48.3 secs

2 T Arai (Subaru Impreza WRX STi) 1:24:50.

3 M Ligato (Mitsubishi Lancer) 1.25.18.8;

4 R Ferreyros (Mitsubishi Lancer) 1.25.21.0;

5, H Al Wahaibi (Mitsubishi Lancer) 1.25.48.8;

6 D Sola (Mitsubishi Lancer) 1.25.59.6;

7 M Rowe (Subaru Impreza WRX STi) 1.26.28.3.