Defending champions Excelsior fought off a valiant Maheno side 26-13 in Oamaru.
The visitors got on the board first after an errant Blues pass hit the deck.
Lachie Kingan stabbed it ahead then Sam McCarthy kicked it ahead twice more and beat everyone to it to score.
Blues were able to hit back with a try of their own a few minutes later.
They finally got their hands on the ball and did well to recycle possession in the rain before impressive youngster Lagi Poasa crashed over.
Maheno snatched the lead back as Ben McCarthy nailed a penalty.
However, it did not last long as Oli Knopp reeled in a clearing kick and saw an opportunity.
He gassed his defender on the outside and found himself in some space.
Knopp scampered downfield and threw a dummy to his outside to beat the final defender and score.
That gave Blues a six-point lead heading into the sheds at halftime and they extended that to start the second 40.
Back-to-back penalties just 5m from their own line had the Maheno defence on their heels.
A dominant scrum then laid the platform for TJ Willie to crash over.
Not going away, Maheno scored through Jackson Attfield to make it a one-score game once again.
However, Knopp’s second try put the score beyond reach with Blues getting the 13-point win.
The wet weather made it difficult for either side to hold the ball for long periods of time but Blues were able to persevere and grind out a tough win.
Their defence was impressive and a real catalyst for getting the job done.
A massive second half powered Valley to a 38-12 win over Kurow.
The game was tied at 12-12 at the break before the competition front-runners ran in 26 unanswered points to keep their unbeaten streak alive.
Athletic Marist secured five points after Old Boys were forced to default.
In such a tight competition, all competition points are valuable and this could come back to bite Old Boys, who now find themselves outside the top four with just two weeks to go.
PRESIDENTS GRADE
With just two weeks until the semifinals, the race for the Burns Shield is heating up.
Presidents Grade frontrunners Athletic Marist have locked up the number one spot on the ladder with 31 points.
Kurow and Old Boys are battling it out for second place with both sides tied on 18 points.
Excelsior is also in the hunt and sits comfortably in fourth place with 10 points and Union are fifth with one point.
