Andy Hessenthaler admitted he always fancied Dover’s chances against Southend but said nothing because he wanted to keep a lid on expectations.
Substitute Ruel Sotiriou’s stunning 84th minute strike was enough to give National League Whites victory over Sol Campbell’s League 1 strugglers before a crowd of 1,754 at Crabble.
Dover boss Hessenthaler had watched the Shrimpers lose 4-1 at Portsmouth in midweek and saw enough then to give him plenty of encouragement ahead of the FA Cup first round tie.
He said: “I was confident but did not want to show that too much to the players because at the end of the day Southend are a League 1 side.
“I watched them with (assistant boss) Nicky Southall against Portsmouth and there wasn’t too much in the game in the first half. It was very tight and Portsmouth scored just before half-time.
“Quietly we were confident if we started the game right.”