United made it through the round of 16, but a two-nil loss to Pennant Hills' Penno FC in the quarter finals means the chase for the cup is over.

Coach Frank Alampi said it was a disappointing finish to a strong campaign.

"We can play a lot better, it was the most disappointing result of the season," Alampi said.

"We played well in patches but we didn't finish off our plays."

In the first half United missed an opportunity to take the lead, however Penno FC made their attempt stick and scored their first.

"We had a good opportunity when we were one-nil to level but we missed it," Alampi said.

United worked hard to build their momentum and several attempts by Leeton to equalise went begging.

An attempt late in the second half bounced off the woodwork and the momentum from that turned towards Penno FC.

Alampi said the further game the went on, the more structure United lost and it allowed Penno FC to "open them up" a bit more.

"They were all over us in that last 20 minutes," Alampi said.

"We were trying to equalise and lost a bit of our structure, they got the second goal with 10 minutes to go."

Alampi said United could have won the game, if they had performed better on the day and to the ability the first grade side had clearly demonstrated during earlier matches.

"It was a good effort to get there (the quarter finals)," he said.

Compounding the disappointment, Alampi said he didn't think Penno FC were as good as the team United beat to qualify to the quarter finals, Kemps Creek United.

Leeton United's coach praised the effort of Joey Fondacaro, who despite nursing an injury niggle, played for the full 90 minutes.

"We had a few out and Joey toughed it out nursing an injury, he played pretty well," he said.

Goalkeeper Jarrod Sillis made some stellar saves for United while Conor Edenden played forward and put in plenty of effort and had some good touches.