Valley (61 points) will be out to repeat last year's 2018 victory in the final when it hosts Old Boys (41) at Weston Park tomorrow while Excelsior (51) will meet Maheno (40) at Whitestone Stadium 2.
Non-qualifiers Kurow and Athletic Marist play in Kurow.
The following week, top qualifier Valley, regardless of tomorrow's results, will meet the fourth qualifier, at this stage Maheno.
However, Maheno can jump over Old Boys providing it wins and Old Boys loses to Valley.
There may be some confident Old Boys supporters after their side beat Valley 40-24 in the previous round.
It was one of only two games Valley has dropped this season.
On opening day it lost to Maheno 19-0.
Valley's strength is in its forwards.
They are strong scrummagers and this is complemented by an efficient, if not brilliant, backline and an astute reader of the game and accurate goal-kicker in first five-eighth Brad McKenzie.
Valley has a powerful front row in Meli Kolinisau, Logan Dunlop and hooker Sam Sturgess while it also has a formidable loose forward trio in captain Cameron Rowland, Junior Fakatoufifita and No8 Jake Greenslade.
Greenslade, who can play in the loose trio or the front row, has 10 competition tries to his credit in the Citizens Shield while McKenzie has scored more than 135 points so far the season.
If Old Boys is to repeat its second-round win over Valley, it will have to improve at the breakdown where it took second place to Excelsior last Saturday.
That lack of ball from the breakdown meant it was unable to build its interpassing attacks from which it has scored the bulk of its victories.
Excelsior is the form team at the moment, having beaten Old Boys all three times this season.
Its win last week against Old Boys was based on vigorous defence and a dominance at the breakdown and it will need to repeat this tactic against Maheno on the No2 ground.
Excelsior won the first round against a depleted Maheno side, scoring 10 tries to four in its 71-28 win but Maheno turned the tables in the second round with a 30-22 victory and, if it can upset Excelsior this week, it could move up to third presuming Valley beats Old Boys.
Maheno, with a fully fit team, has real ability.
It has been weakened during the season by injuries but it has the ability to play above itself.
It defeated Valley 19-0 at the start of the season but Valley won the next two encounters, 38-19 and 42-12.
Maheno, led by the hooker Hayden Tisdall, flankers Jackson Attfield and Marcus Balchin and No8 Josh Clark might well match Excelsior up front.
- Terry O'Neill