Northants County edged a tight home contest with Wellingborough in Group A of the NGU Junior League by the scoreline 4-2 to book their place in the semi-finals.
Sam Walton gave the visitors the lead by beating Matt Myers 2&1 in the opening tie, while Wellingborough team-mate Dominic Holden outplayed Andrew Brown in game five.
Needing just one more win to secure top spot in the division, Wellingborough were unable to complete the job as the home side grabbed the other four points.
Rhys Taylor beat Ellie Darnell 3&2, Emily Cotton also triumphed on the 16th hole, while Cameron Grundy and George Elderton collected the last two points with one hole to spare.
Priors Hall also ended their Group A campaign with a 4-2 away defeat as they lost at Whittlebury Park B.
A draw at Peterborough Milton B proved decisive for Brampton Heath as they clinched a last four spot without losing a match in Group B.
Brampton, who recorded a big win at Collingtree in their opening fixture, went on to beat Kingsthorpe and Staverton on their home tracks.
Milton completed their campaign on a high as they picked up three comfortable wins in a 4-2 home success against Kingsthorpe.
Whittlebury Park A strolled through to the semis with a dominant 5-1 home victory against Peterborough Milton A in Group C.
After drawing at home to Northampton in their previous game, Whittlebury made a great start as Sam Henfrey took the first point with six holes to spare.
Mitchell Edwards triumphed on the 18th, John Heath won 4&2 before Charlie Salter wrapped up the home victory with a 2&1 success in game four.
Although Peterborough got on the board with a 2&1 victory, the home side completed the scoring with a 2&1 success for Fergus Robinson in the final match.
Overstone Park will need to thank Silverstone for reaching the semi-finals after their Group D competitors recorded a surprise 3½-2½ home victory over Cherwell Edge.
With Cherwell only needing a draw to top the standings, Silverstone looked set for defeat when they could only field four players.
Alexander Sexton (7&5), Ellis Tiffin (one hole) and William Wood (one hole) did the home side proud with wins, while Natasha Ainsley’s half in the second game clinched the team victory.
Northants County face Brampton Heath in the first semi-final at Kingsthorpe GC on Sunday, before Overstone Park take on Whittlebury Park A at the same venue.