Auckland, Tasman, Wellington and Canterbury have pulled clear of the rest and appear set to contend for the Mitre 10 Cup Premiership title.
With three weeks remaining those four have all but sealed their places in the top four.
Auckland pipped Taranaki 31-30 in New Plymouth to stay unbeaten with six wins from six.
In next weekend's feature matches Auckland play Otago, Wellington play Tasman and Canterbury play Hawke's Bay.
Waikato, Hawke's Bay, Northland and Otago are the top four in the Championship.
Canterbury and Counties Manukau share the lead in the Farah Palmer Cup.