Following a first half without a goal, Premier League Hull took the initiative after the restart and went on to book their place in the last 16 courtesy of two unanswered goals from Matty Fryatt.
You can find out how the match unfolded with our minute-by-minute updates below.
"We can't win the Premier League, but a Premier League team can win the FA Cup. [Roots Hall] hasn't changed in 30 years. It's Southend's final and it will be the first time in five and a half years that this ground is full. We're treating the tie with the respect it deserves. We have got to match their endeavour and work rate."
"I felt we didn't need to change anything from last weekend's win. He only trained yesterday," said Brown. The centre-forward will be introduced to the crowd before the match, though.
"I believe that, had I stayed, we would have survived a second season in the Premier League and, with that new training ground, we would have remained a Premier League club for 20 years. The new chairman did not share that vision. He was a short-term man and that is no good to me. Maybe for that reason alone, it was best that we did part company."
“You only have to look at what Bradford City achieved last season to see a cup run can be a real positive. What they did was incredible and getting to Wembley was a fabulous achievement," he said.
"They beat three Premier League sides on their route to the final, and that has given a lot of lower league teams lots of confidence. We’re going into this game with Hull full of belief, and I believe that if we play as we have been doing, there’s nothing stopping us copying Bradford and knocking out a Premier League side."