"We've been kind of just tracking under the radar," said Celtic coach Duane Brown.
"With Marton this week, we're not looking at it as a Shield game, it's do the job and make the semis.
"If you don't scramble on D, they'll hurt you."
Having lost nine players from last year's campaign to injuries or promotion into their club's Premier squad, Saturday's win over Kaierau was a great display of character on an afternoon where mud-covered forwards struggled to distinguish friend from foe.
"If they're running the other way, you had to tackle them," said Brown.
"It sure was pretty muddy alright; it rained the whole 80 minutes.
"Physical first half, Kaierau probably had most of the ball. If you count how many times we made it into their half, it was probably two.
"Defence won the game, at the end of the day."
Scoreless at halftime, Marist knew the first team to register points would set the tone, and it was lock Caleb "Maps" Jones – nicknamed because he gets lost before trainings – who scored off a pick-and go.
Another Jones bust saw workhorse veteran Ross Pui toe the ball ahead to score, and then talented halfback Kobe Millar, who debuted for Celtic alongside his father last year, dotted down to make them safe.
The Senior draw is:
June 26, 1pm kickoffs (times subject to change): Taihape vs Pirates, Memorial Park 1; Marton vs Celtic, Marton Park; Hunterville vs Buffalos, Hunterville Domain; Kaierau vs Utiku Old Boys, Country Club; Counties vs Ratana, McNab Domain; Ruapehu vs Border, Rochfort Park.
