First leg recap - Stevenage 1-1 Southendpublished at 19:09 British Summer Time 14 May 2015
It's all to play for at Roots Hall after Sunday's meeting at the Lamex Stadium finished all square.
Dean Parrett put Stevenage in front six minutes into the second half with a shot from 25 yards.
But Boro's lead lasted only nine minutes as Barry Corr headed in Southend's equaliser.
There had earlier been an eight-minute delay during the first half after Southend's Michael Timlin and Stevenage captain Bira Dembele clashed heads.
Timlin needed 15 stitches in his wound and Dembele seven. Ouch!