Former Saints midfielder Matt Oakley praised the "fantastic" home support after Derby's victory.
But he said the taunts from sections of the home crowd helped him drive his team onto victory.
St Mary's was a cauldron of noise as the two teams ran out of the tunnel for kick-off.
And the decibel levels rose even higher seven minutes later when Andrew Surman curled Saints into lead.
But inspired by captain Oakley, who played a key role in both of Steve Howard's goals, Derby hit back to take a 2-1 lead into tomorrow's second leg at Pride Park.
Oakley, who spent 12 years at Saints before leaving last summer, said: "The atmosphere and the Saints fans were fantastic, especially at the beginning,.
"I was expecting that because they always get behind their team.
"Obviously it was a big occasion for me coming back here because I was here for 12 years and I got a bit of stick from the fans and called a few names. But that just fired me on even more.
"As soon as fans do that I know I am playing well and they are trying to put me off my game, so I was pleased with the way I played."
For full story see today's Daily Echo.
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