Walla jumped to top spot and booted Henty out of the top six on Saturday.
The home team overcame a poor start with the ball to strangle Henty in a two-run thriller.
"We bowled terribly in our first 15 overs and then in the last 25, we really hit out straps and put the pressure back on them," Walla captain Tim Simmons said.
Walla was bowled out for 142 but in something you don't often see, was able to restrict Henty to 140, even though it had five wickets left.
"To be fair, Walla's a slow ground, a 140-odd there is like a 180 at most other grounds," Simmons offered.
Kieran McCarthy compiled 49, while Henty's Sam Terlich took 3-13.
In only his second game for the season, first drop Grant Gardiner was unbeaten on 52, while middle order batsman Daniel Hore-Smith scored 28, in just his third game.
Seam bowler Mitch Lauritzen bowled a tight line to claim 2-12 from five overs, while Simmons also chipped in with a double.
"Kieran McCarthy has been unreal for us the last two weeks with bat and ball, he's taken his game to a new level, while Mitch Lauritzen bowled really well, they just didn't give them anything to hit," Simmons suggested.
Walla leap-frogged Brock-Burrum for top spot.
Brock-Burrum lost that mantle after a second straight loss.
Culcairn hammered the one-time premiership favourites.
The visitors compiled a sound total of 156 from only 36 overs with opener Vince Chaffey (36) maintaining his consistent recent form, while No.8 Riley Knobel contributed 30 not out as Doug Watson claimed 4-26 from only four overs.
The home team was humbled for just 74 with Dai Jenkins (5-4 from eight overs, including six maidens) claiming the best figures in his decade-long stint.
Rand had no issues in toppling Lockhart.
The home outfit tallied 143 with Zach Burkinshaw top-scoring with an unbeaten 49.
Daniel Lieschke, who's fifth in the wicket-takers, was dynamic with 4-19.
Bryce Swift (73 not out) and Mark Kreutzberger (48) guaranteed the win.
Osborne's Ed Perryman cracked an unbeaten century in the six-wicket win over Holbrook.
The visitors had first scored a competitive 5-183 with Corey McCarthy making 52.
Perryman's unbeaten 106 is his third for the club and second since it joined the competition in 2018-19.
ALSO IN SPORT:
"I was really happy with how they went."
And cellar-dwellers Walbundrie looked set to jump off the bottom when it hammered 7-206, with Hayden Wardius (66no) and Jacob Miller (53) in fine touch.
However, The Rock-Yerong Creek's Ryan Kirkwood (82) and Todd Hannam (69) were vital in a nine-wicket win.