Reading will have a home tie in what could be a crucial second leg encounter in their Division One play-off after they beat Watford 3-0 at Vicarage Road.
The win means Reading's prospective play-off opponents in Nottingham Forest or Wolves cannot overtake them and gives the Royals what could prove a vital home advantage.
Tony Rougier, Darius Henderson and Jamie Cureton scored for Reading against a Watford side with just a higher league position as their incentive.
Allan Nielsen forced Reading keeper Marcus Hahnemann into the first save of the evening from a fierce 20-yard drive, before the Royals took the lead from their first chance of the game.
Ricky Newman crossed from the left for Rougier to head past goalkeeper Alec
Chamberlain for his fifth goal of the season.
Jason Norville sent a shot inches past the post in the 28th minute as Watford looked for a quick response, but the visitors were dominant.
Watford started the second half brightly as Micah Hyde forced Hahnemann into a fine
diving stop with a volley from distance.
Tommy Smith then let fly with a 30-yard effort that whistled inches wide.
Defender Sean Dyche then spurned a golden chance to equalise on the hour, heading a Neal Ardley corner straight into the arms of Hahnemann from close in.
Watford could not convert their pressure into goals and Reading made them pay when they snatched a second goal in the 70th minute.
Cureton crossed for and Henderson slammed home.
Cureton then added the visitors' third when he unleashed an unstoppable shot into the top corner with keeper Alec Chamberlain stranded.
Watford: Chamberlain, Mahon, Dyche, Gayle, Glass, Ardley, Vernazza, Hyde, Nielsen, Tommy Smith, Norville. Subs: Brown,
Johnson, McNamee, Lee, Fitzgerald.
Reading: Hahnemann, Brown, Watson, Viveash, Shorey, Rougier, Hughes, Newman, Sidwell, Tyson, Henderson. Subs: Mackie,
Cureton, Ashdown, Campbell, Castle.
Referee: T Bates (Stoke on Trent)