Southampton saw off West Brom 3-1 at St Mary's on Friday to set up a Championship play-off final showdown with Leeds United. (More Football News)
Leeds thumped Norwich City 4-0 at Elland Road 24 hours earlier to book their place at Wembley, where Southampton now await on May 26.
The first leg between the Saints and West Brom finished goalless - just like the other semi-final - but the home side's quality told in the end.
Russell Martin's side dominated the first-half possession, with David Brooks going closest to scoring with a shot that hit the outside of the post.
Southampton made the breakthrough via a powerful Will Smallbone finish four minutes into the second half after Gray Diangana lost possession.
Darnell Furlong had a shot helped over by Alex McCarthy, while David Brooks - who assisted the opener - had a strong penalty appeal rejected.
Southampton remained in control, though, and Adam Armstrong scored a second with a shot through Furlong's legs and past Alex Palmer.
Armstrong's second goal arrived from the penalty spot in the 86th minute after Tom Fellows fouled Ryan Manning in the box, rendering Cedric Kipre's late header a mere consolation.