Halstead (333-6) beat Frinton-on-Sea (226-5) by four wickets
Halstead skipper Josh Wells hit an unbeaten 173 off just 107 balls to lead the Star Stile team to victory over Frinton at home.
Halstead openers Chris Huntington (13) and Mark Johnson (18) started the innings solidly before Neale Dakin stepped in at number three and ramped up the run rate.
He hit 76 off 105 balls to significantly boost the Halstead total, before Wells blasted it out of reach.
Wells hit the boundary 27 times, including one six, as he racked up the impressive score.
Charlie Douglas-Hughes (33) added the extras as the home side reached 333-6 in their allotted 50 overs — with Wells remaining not out.
Frinton gave it their all in reply, but could not come within 100 runs of the total set.
Michael Armstrong (91) and Miguel Machado (57) had good knocks and Sam Brynes (42 not out) approached his century.
But they were unable to catch the massive total set by the home team, who hit the boundary 50 times.
Huntington (2-41) and Sam Walter (2-47) were the pick of Halstead’s bowlers, during their 10 over stints.
Halstead next face Mistley away from home on Saturday (1pm).
n In Division Three, Tuddenham (213-3) beat Halstead II (211-9) by seven wickets.
Halstead won the toss and elected to bat first.
Ian Pont (47), Adam Morris (44), Harry Pritchard (30), Mark Surridge (26) and Cath Dalton (25) hit most of their runs.
The team play Mistley II at home on Saturday (1pm).
n In Division Seven, Sudbury III (217-4) beat Halstead III (210-8) by seven runs.
Sudbury won the toss and batted first, with opener Willie Amos posting 109.
Despite a team effort at the crease in reply, the side fell short by seven runs.
They play Mildenhall IV on Saturday at home (1pm).