Horsham captain Michael Thornely was delighted with the mature innings by teenager Tom Clark, whose unbeaten 147 paved the way for them to beat Bexhill by 77 runs.
The result combined with Roffey’s defeat at Hastings, gives Horsham the chance of finishing runners-up in the Premier Division.
They travel to East Grinstead on Saturday in a fascinating battle between first and third, with Horsham who are 37 points behind Roffey in second, looking to complete the double over the title-favourites.
Sussex academy player Clark, 16, gave a masterful display with 22 fours and one six coming in his knock which was unbeaten over 139 balls.
He joined forces with Nick Oxley (47) who combined to score 72 runs for the third wicket.
Clark also produced a brilliant 95-run partnership with overseas player Mika Ekstrom for the sixth wicket.
Horsham scored 288 for 6 from their 50 overs.
Thornely said: “Winning the toss and getting 288 was a nice target to defend.
“Tom scored his first century for the first team and to not just get 100 but get 147 is amazing for the first team. It was excellent.
“He showed a good temperament and constructed an innings which not many young people do nowadays.
“To pace it over the 50 overs was very good to see. He hit it all around the ground and it was very difficult to set fields for.”
Bexhill reached 211-9 in their reply from 45 overs.
Medium pacer John Aston took 5-38 and opening bowler Ekstrom grabbed 2-33.
Thornely said: “Bowling on what was a good wicket, we didn’t bowl as well as we have done recently and at drinks Bexhill were 140-3.
“John Aston bowled beautifully and made sure if batsman made a mistake, it cost them.
“The wickets started to fall regularly in the last 15 overs and the result was inevitable.”
Thornely has not ruled out clinching runners-up spot with a final push in the last two games.
He said: “We might be able to grab second - the goal is to win our last two games against East Grinstead and Ansty.
“We beat Grinstead easily early in the season. They have easily been the best team so it will be a tough game and we’ll have to play like we did against them before, this weekend.”