They are two points clear of Waitakere, who hold a one point buffer over Auckland City and Canterbury United, with Hawke's Bay United one point further back.
Auckland City have the easiest road to securing a playoff spot, holding two games in hand and having picked up a comfortable three points with a 2-0 victory over the Wellington Phoenix Reserves.
An early strike from Fabrizio Tavano was supplemented by a Clayton Lewis penalty in the second half to snap Auckland's three-game winless run in the Premiership.
Canterbury United also got back to winning ways with a vital 2-1 victory over Hawke's Bay United to sit in fifth spot on the ladder.
They needed to come from behind to do so, after Ross Willox put Hawke's Bay ahead late in the first half from a corner.
However, Canterbury equalised in the 63rd minute through substitute Juan Chang, and Hawke's Bay were reduced to 10 men soon after when Finn Milne was sent off.
The depleted Bay ranks nearly held on for a point, but Aaron Clapham struck in the 85th minute to give Canterbury a big boost in their playoff quest.
Hawke's Bay are still in with a realistic shot of making the playoffs however, finishing their season with three games against bottom-four sides.
At the foot of the table, Tasman United jumped off the bottom of the ladder, overtaking Southern United after picking up a 1-0 win over Hamilton Wanderers.