Whitaker is level with Lauder at third overall in the series standings, representing a great improvement for Whitaker who had been ranked seventh overall after round four.
The 33-year-old Lauder took a cautious approach to his racing on Saturday.
"The course was a mix of open farmland, with some pine tree sections too, and I was on minute one and among the first riders to be sent onto the track. I thought I'd be cunning and let the other two riders with me go ahead, so that I'd have wheel tracks to follow and it worked out for me."
Reardon currently holds the ace cards in terms of overall championship glory – he is leading the standings after five rounds and the rider immediately behind him, Waikato's Taylor, is a massive 23 points adrift.
Reardon will be hoping he can hang on to the lead when the competitors next race, at the double-header final weekend, rounds six and seven, in Hokitika in three weeks' time, on July 19-20.
With the scores from only six of the seven rounds to be counted – riders can discard their one worst result – the race for the championship win outright, and for the various class titles too, could still go down to the wire at Hokitika.
2019 Yamaha NZ Enduro Champs calendar:
Round 1: Saturday, March 16 – Thames.
Round 2: Saturday, April 6 - Kapiti.
Round 3: Saturday, April 20 – South Waikato.
Round 4: Sunday, June 9 – Martinborough.
Round 5: Saturday, June 29 – Bideford, Masterton.
Round 6: Friday, July 19 – Hokitika, Westland.
Round 7: Saturday, July 20 – Hokitika, Westland.