Russell Slade called on Leyton Orient to finish the job at Wembley after their League 1 Play-Off Semi-Final win over Peterborough United.
Second-half goals from Dean Cox and Chris Dagnall put Orient in control of the second leg and although Conor Washington pulled one back in stoppage time for Posh, the hosts held out for a 3-2 aggregate success.
"I'm a very proud man, the players were inspirational and so were the crowd," said O's boss Slade.
"I've never seen anything like that in the four-and-a-half years since I have been here.
"It was like a football club being reborn, there was a real belief around the stadium, a real togetherness which is what was needed.
"It was a fantastic night and I"m sure it will live on in people's minds, we've achieved something remarkable already by getting to Wembley but there is still so much more work to do.
"We are not going there just to make the numbers up. We are going there to get to the next level."
After a goalless first half Cox blasted the opener on the hour when his free-kick rebounded back to him on the edge of the area.
As time ticked down Dagnall collected a cut-back from fellow substitute Shaun Batt to hit the second before Washington bundled home a consolation in injury time.
Orient, who led the table for much of the campaign only to fall away during the run-in and finish third, are now just 90 minutes from following Wolves and Brentford into the Championship next season.
They will make their first trip to Wembley in 15 years where they will take on the winners of Thursday's second leg between Rotherham and Preston.
Posh, by contrast, face another season in League One following last term's relegation.
They had their chances but fluffed their lines in front of goal, not least when Danny Swanson opted to shoot from the angle rather than cross for 33-goal Britt Assombalonga to tap in.
"The difference on the night was they were more clinical," admitted manager Darren Ferguson.
"To have four three on three situations in the first 45 minutes and not take advantage of any of them, that was our downfall.
"In my opinion I don't know if Orient have done enough over the two legs to go through, but they have done.
"So I have to congratulate Orient and I really hope they go on and win it now."