Potton were made to pay for defensive errors as they fell to a disappointing 3-2 defeat at Wembley on Saturday.
Back in October Potton had faced Wembley at the Hollow and won 4-0. Saturday was a different affair as the hosts, who fielded only two players from that earlier match, were a much different opponent.
A threadbare Potton were without the injured Aaron Murrell and Tom Blatch, and Jonny Hall was unwell meaning that manager, Steve Kuhne, was named on the bench.
Potton lined up with an unusual 4-4-1-1 with Martin Danobrega playing behind the lone forward of Jim Burnside. James Sage was at left back with Christian Smail dropping into the back four from his usual midfield role.
Wembley deservedly took the lead on 12 minutes as Carl Tappin was easily beaten by the impressive Iley who delivered an excellent cross that was converted by the towering Ebonine.
Just two minutes later and the hosts doubled their lead when this time Ogunsola was given too much on the edge of the box by a retreating Gareth Hunt to slot home from 18 yards.
Wembley then increased their lead with the goal of the game on 22 minutes when Iley picked up the ball 10 yards inside in his own half but was able to run without a tackle being made before slotting home from five yards.
Potton though regrouped with Sage returning to centre half, Tappin moving to left back and Smail to right back and this seemed to nullify the Wembley attacks.
They got a goal back on the half hour when a free kick was awarded 20 yards out and Ryan Don converted with some style to give the Royals some hope.
With the wind and the slope now in their favour it was crucial for Potton to score next in the second half if they were to get anything out of this game.
Potton reduced the deficit further on 58 minutes when Gareth Hunt won back possession and passed to Jim Burnside who was brought down in the box. Danny Webb converted with ease for his 15th goal of the season.
This was as good as it got for Potton though as even though United has the majority of possession for the remainder of the game apart from a Mo Ahmed chance created by Gary Ansell Carter on 75 minutes, they offered little going forward.
Potton are at home on Saturday when they take on Colney Heath.