The firsts suffered their first defeat of the season going down by 26 runs to St Margaretsbury but remain among the leaders in third place in Division 2a.
Both teams entered the game unbeaten and The Park gave themselves hope by bowling out the visitors for 201.
But a poor start in response left them in disarray at 54 for 5 before a brilliant innings of 61 by Dave Roberts supported by Charlie Randall 25 and Tom Matthews 24 salvaged their cause.
As the overs ebbed away victory remained possible but Roberts gamble to hit one more six didn't make it and hopes disappeared and they were bowled out for 176.
Earlier the visitors batting had a handy start but once Knebworth switched to slow bowling momentum changed.
From 70 for 0 they slipped to 83 for 4, but thereafter the lower order lifted them to 201 all out.
Louis Champion 3 for 27 and Alex Richmond 3 for 37 inflicted much of the damage while later Matthews bagged 2 for 22.

Abe sets up easy win for 2s
The 2s stormed to a ten wicket win over Welwyn Garden City 3s to remain among the leaders in Division 6a in second place.
Abe Gibson 4 for 12 and Saicharal Nandyala 2 for 11 bowled the hosts out for 91 and then Mark Winchester and James Hobbs guided them home with 39 apiece.

Thirds suffer defeat at Brox
The 3s recovered from 45 for 6, but in the end went down by 33 runs away to Broxbourne 4ths.
Rahul Rawat with 3 for 11 was the pick of the bowling in reducing the home side to 152 for 9.

Richard's 70 boosts 4s
A fine 70 from Richard Hollis was unable to stave off a 34-run defeat for the 4s at home to Letchworth 6s.
He received support from Seb Ambrose 27 not out as they were bowled out for 137 in reply to 171 all out, Seb also bagging four wickets