Waikoikoi and Metro Cubs are the first teams to book themselves a place in the Combined Country competition top six semifinals with two round-robin games still to be played.
Waikoikoi and Metro remain unbeaten and 12 points clear of fourth place, although the four competition points came a little easier for Waikoikoi on Saturday than for Metro.
Waikoikoi claimed the points without a ball having to be bowled with Waikaka defaulting.
Metro, however, were made to work overtime against Riversdale in what turned out to be a thriller.
Batting first at Metro the home side put together 225 for seven from their 40 overs, thanks mainly to yet another century by skipper Karl McKee.
It was McKee's second successive hundred after also posting one against Waikaka.
Riversdale openers Willy McKee (89) and Hamish Blakely (36) put the visitors in a strong position but Zak Kelly, in particular, was able to haul back Riversdale to take the game down to the wire.
Metro ended up winning by just one run.
Wyndale also grabbed a tight victory on Saturday against the Appleby Cannons.
Appleby posted 221 for seven batting first, with James Hargest College pupil Jono Allen top-scoring with 75.
Wyndale snuck home with one wicket to spare thanks mainly to former Southland and Invercargill-Old Boys players Dale Cocker (67) and Scott Gutsell (58).
Nathan Smith was a standout with the ball, taking four wickets. Earlier he compiled 35 with the bat.
Central-Western confirmed their status as one of the frontrunners in the bottom six section with a 115 run win over the SBHS Colts.
The students did well to restrict Central-Western to 189 for eight batting first but could only manage 74 in reply.
Wyndale 222 for 9 (Dale Cocker 67, Scott Gutsell 58, Daniel Thwaites 27*, Nathan Smith 4-39, Rick Rima 2-28) beat Appleby Cannons 221 for 7 (Jono Allen 75, Nathan Smith 35, Nathan Sutton 2-28, Devon McLeod 1-12) by 1 wicket
Metro Cubs 225 for 7 (Karl McKee 113, Jon Henery 40*, Luren Els 3-36, Bill Wilson 2-16) beat Riversdale 224 for 8 (Willy McKee 89, Hamish Blakely 36, James McKee 26, Zak Kelly 3-25, Danny George 2-44) by 1 run
Waikoikoi beat Waikaka by default.
Central-Western 189 for 8 (Rowan Findlay 49, Phil Garaway 25*, Connor Wells 19*, Tom Capil 2-25, William Clapperton 2-25) beat SBHS Colts 74 all out (William Clapperton 15, Tom Capil 14, Gareth Paul 3-18, Quinn Stewart 2-17, Connor Wells 1-7) by 115 runs
- The Southland Times