Otago Boys' has already toppled the Christchurch side on the road once this season, 29-7, in their annual interschool match last month.
At stake this time is a spot in the top four schools competition in Rotorua next weekend.
A week after toppling archrival Southland Boys' High School 16-10 to win the Highlanders First XV competition, Otago Boys' coach Ryan Martin was aware of the challenge in front of his team.
''I think ... for us to go up to Christchurch Boys' on home ground and beat them, that's the mental aspect for us.
"Because it's a very daunting ground, they have large crowds that turn up and they get pretty excited.
''We absorbed all that pressure last time. For us it's quite comforting knowing we have been there and done that already this year,'' he said.
Otago Boys' is coming off a solid week's training and focused on countering Christchurch Boys' expansive style of attack.
''They like to use a lot of width in their game, so obviously we are looking at combating that with our defence just being a bit more aggressive ... especially at ruck time, as well,'' Martin said.
He singled out Christchurch Boys' midfielder Alex Nankivell as a threat with ball in hand, but backed co-captain Sio Tomkinson, the ''best defensive midfielder in New Zealand [schoolboy rugby]'' to handle him.
Despite drizzle being forecast in Christchurch this afternoon, Martin was not worried.
''We can go in and out of different styles. If it's hard and flat that suits us; if it's wet that suits us; if it's going to be greasy and windy we can move into that type of game as well.
''That's probably why this team is so special; we can play different styles of rugby depending on who we play and the conditions,'' he said.
A week after struggling to string phases together, Otago Boys' will look to lay a strong platform up front for its backs, beginning with its mighty scrum.
Led by loosehead prop Jonah Aoina, who has scored 18 tries so far this season, Alex Frood and Sione Asi, the Dunedin side should be able to stack plenty of pressure on at scrum time.
Openside flanker Slade McDowall will also be a key cog in the Otago Boys' pack at the breakdown.
His side needs to generate some good quick ball so Sam Porter and Tomkinson can unleash their outside backs.
Discipline will also be key, a week after playing 20 minutes against Southland Boys' with 14 players.
Martin had a fully fit squad to pick from for the match and stuck with the 22 that won last weekend.
Christchurch Boys' manager Mike Drury said his team could not let its standards drop the way it did when the teams last met.
''Last time we were poor with ball in hand. We need to prize possession a lot more if we are to beat Otago.
"We managed to make some good busts in the backs but our support play needed to be better.
''We are respectful of the Otago team. We realise we dropped our standards when they came here a couple of months ago.
"We need to shut down their big men, while giving our key attacking forces in the backline quality ball so that they can show their wares.''
Drury said Christchurch Boys' flanker Sean Forster and midfielder Nankivell need to win their respective match-ups against McDowall and Tomkinson if his side was to win.
In Oamaru, St Kevin's College will host Christchurch's Burnside High School in the South Island co-ed final this afternoon.
The winner will advance to the top four co-ed schools competition in Rotorua next weekend.
- Robert van Royen
Otago Boys' HS v Christchurch Boys' HS
Christchurch Boys' High School, today, 1pm
Otago Boys': Jonah Aoina, Alex Frood, Sione Asi, Jarrell Pattison, Matt McNamara, Matt Heffernan, Slade McDowall, Jamie Mowat (co-captain), Kadin Brocks, Sam Porter, Chris McNoe, Sio Tomkinson (co-captain), Hemaua Samasoni, Josh Buchan, Matt Jones, Kabe Calder, Liam Sharples, Isimeli Tuivaga, Ricki Jackson, Tim Hogan, Mike McKay, Mitch Kelly.
Christchurch Boys': Henry Lissaman, Jim Smith, Ethan Simpson, Nathan Evans, Connor Imeson, Jacob Vincent, Sean Forster (captain), Jesse Houston, Nick Johnson, Josh McKay, Cam Hay, Alex Nankivell, Faletui Samuelu, Fraser Scott, Hayden Webber, Matt Birt, Kilipati Lea, Jack Hauschild, Nathan Schuurman, Dayne Corbishley, Ben Chippendale, Chris Whitley.
