Paul Sturrock paid tribute to super-sub Bilel Mohsni after the striker's late double fired Southend back to the top of League Two.
Crewe full-back Harry Davis cancelled out Kane Ferdinand's first-half opener only for Moshni to come off the bench and seal all three points with two goals in the last three minutes of the game.
That secured a 3-1 victory, much to the delight of Sturrock.
He said: "Bilel gave us an extra threat and he and Ryan Hall coming on changed the game. I told him to get in the box as soon as Hall crossed it. It seemed to work.
"Hall is a crossing machine and if you have a man the size of Bilel coming in at the far post, he is going to score goals.
"I was very disappointed with conceding but Crewe deserved to get an equaliser. But the players are showing their character. They weathered the storm and are made of hard stuff."