A last gasp equaliser for Billericay against Folkestone, scored by Jamie O'Hara, ensured a 3rd place finish for the first team after they won 2-1 at Leiston.
After a goalless first half, which the Greens had the better of, two goals in a minute from Ashley Nathaniel-George and Daniel Uchechi just after the hour mark ensured that Leiston had to work hard to get something out of the game.
But that's exactly what Leiston did, and they pulled a goal back through Joe Marsden a few minutes later, and Tom Lovelock made a superb save late in the game to ensure the lead was kept.
With Folkestone only picking up a point, the Greens finish ahead of them in 3rd place on goal difference.
The play off sem final will be played at SJP on Thursday evening, kick off at 7:45pm. Full details will be made available as soon as they are confirmed.