Old Boys, chasing its fourth consecutive Citizens Shield, is unbeaten and has picked up maximum points in all four matches, scoring 33 tries and conceding nine.
Athletic Marist has won three of its four games - it was beaten 26-24 by Valley - scoring 22 tries and conceding just five.
Old Boys' mobility around the paddock and its ability to counterattack may be the vital difference between the two sides.
Loose forwards Sale Pi'i, Lio Havilli and Samisoni Tangotongo are all impressing with the ball in hand, and Pi'i is a match-winner with his pace and size.
Harry Frost made an impression at halfback against Excelsior with his long, swift passing and timely probing, and goal-kicking first five-eighth Tai Aholelelei will be expected to add to his points tally of 62 this season.
Athletic Marist has not yet fashioned a satisfactory 80 minutes of rugby.
The pack is physical, and the backs, when they decide to play their natural game and exploit space, can be dangerous, although too often this has been negated by individuality and wrong option-taking.
Big wingers like Setelo Akau can be dangerous if given real opportunities. Halfback Zac Bartlett has proved to be an accurate goal kicker.
The curtain-raiser pits fourth-placed Excelsior against Kurow, which has yet to win a game this season.
Excelsior beat Valley and Maheno in its first two games but it was only a try in the dying seconds that gave it the win over Maheno.
Excelsior has had difficulty in fielding a full bench and has lost its last two games, to Athletic Marist and Old Boys.
Kurow, has struggled with the loss of coach Richard Pledger to Wanaka and a paucity in depth of players.
Valley, now in third place, six points behind Athletic Marist, will meet Maheno, a side which has grown in confidence since its win over Kurow a fortnight ago.
Maheno is relatively youthful and plays a pleasing brand of rugby. Valley should not take the side lightly.
North Otago coaches Mike Mullins and Troy Looms have named a 37-man squad to prepare for the 2014 Heartland Championship.
Newcomers include Don Lolo, Sana Nahuto, Jamie Robb, Harry Frost, Kayne Middleton, Joe Marston, Jared Whitburn, Wayde Hodgen and Kilioni Taufa.
