The seconds won their final game, a crucial one on a last day of the season, where four teams including their opponents Welwyn Garden City 3rds were in a four-way tussle to avoid the drop from Division 6a.
In the end they cantered home by eight wickets and their visitors also escaped relegation.
WGC started well with bat ticking the scoreboard along nicely until the 20th over when Graham Fisher was brought into the attack to bring about some control.
He, along with Ross Courtney, wrestled back momentum restricting WGC to 114-2.
Fisher rolled back the years to help with a procession of wickets, taking 4-25, and along with the introduction of Scott Page 4-16 from his five overs, eventually bowled out WGC for 184 in just under 44 overs.
During the tea break, the weather gods reared their ugly head, eventually enabling play to resume with a revised total of 133 needed from 36 overs.
Mark Woods, requiring 31 to reach 500 league runs and cap off an excellent season with the bat, unfortunately fell early and not long after James Hobbs was out lbw.
Rob Morley joined Courtney at the crease and both started carefully to ensure Knebworth avoided a collapse.
At the half way point they were 44/2 still some 90 runs needed before both stepped up their intent in the run chase.
Indeed, Morley (65 not out ) and Courtney (41 not out) managed to see Knebworth home with six overs to spare and a win by eight wickets to ensure they avoided relegation.
Having survived the drop Park can look back on an excellent second half with six wins out of nine after having lost their opening seven games.