The leader has 13 points and 19.5 games to be four points and three games ahead of the Otago Gold and Otago Blue teams, which are tied for second place.
The long awaited clash between St Clair and defending champion Otago Blue will be played at Balmacewen on Saturday, but even a good win for the Otago Blue golfers will not topple St Clair on the leaderboard.
Island Park is clearly in fourth place with seven points and 16 games after beating Taieri 4-2 at Taieri.
Otago Blue continues to graft its way back after suffering two early losses and beat the Otago Gold sextet 5-1 at Balmacewen.
The match between St Clair and Chisholm Park was close. Two of St Clair's wins finished on the final green and the other three concluded with one hole to spare.
Brent Butler gave the Park team its only win, beating schoolboy Connor Ross by a solid 4 and 3 margin.
Island Park, the first nine hole course to enter a team for two decades, is competing well and had an impressive 4-2 win over Taieri.
Andrew Hobbs won the battle of the No1 players, beating Mark Andrews, while Taieri No2 Brett Kennelly evened the score, downing Island Park captain Michael Minty in 17 holes.
Taieri was without the services of Callum Stringer, who had a back injury, and his place was taken by his father, Craig, who lost to Park's Kelly Adam in 15 holes.
Island Park's Gary Creedy won the battle of the masters triallists with a narrow win over Ken Shaw, while Michael Wray posted a 2 and 1 win over Craig Robertson.
For Taieri, No5 Ian Boath continued his good form, beating Nicholas James 5 and 4.
After losing its first match against Otago Gold, Otago Blue did not make the same mistake for a second time, winning the first five games.
Brandon Hodgson and Duncan Croudis won by convincing margins while Michael Smith and Tyrone Ratahi posted 2 and 1 wins.
Gold captain John McIntee had an impressive 3 and 2 win over Jason Hughes, to give his team its only win.
The battle between the No1 golfers was again a tight tussle, requiring all 18 holes.
This time, the result was reversed, as Blue No1 Nick Borren headed schoolboy Harry Smith by the narrowest of margins.
