A shock defeat away at Chichester ended Horsham’s four-game winning streak and allowed leaders Preston Nomads to reaffirm their cushion at the top of the Premier League.
A high-scoring game in bright conditions saw Will Williams hit a best of the season 87 as Horsham made 270-8 from their 58 overs.
But hosts Chichester were rewarded for their attacking stance in reply as the top three batsmen all delivered to see the big target eaten up.
Having closed in on Nomads last week the defending champions beat Worthing to stretch the gap at the top back out to 33 points.
Horsham skipper Craig Gallagher said: “The last years we’ve finished second we’ve looked back at games we should have won and I hope this doesn’t turn out to be another. There’s no more room for slip ups.”
Gallagher won the toss and in ideal conditions chose to bat.
The plan to score big and put pressure on the home side largely worked with New Zealander Williams the big scorer, helped by contributions further down the order.
Williams and Sam Attfield made a 50-run stand for the fourth wicket, Attfield with 37 from as many balls before he was trapped LBW by Chi opening bowler Matt Geffen, who took 4-87.
Wicketkeeper Sam Bell made 30, Paul Williams 36 and Stuart Whittingham 30 from 20 balls as the visitors eased past maximum batting points.
In reply Chi’s opening pair Mark Bamford and Chris Kirkham went for it from the off. Bamford hit 42 from 31 balls in a 55-run opening stand. Ashton Turner (62) joined Kirkham (77) at the crease and the pair added 132 to inflict the real damage and put them on the path to victory. Spinner Michael Munday took another six wickets.