Albion's challenge for the play-offs is back out of their hands with a game to go.
Reading came from behind to win 3-1 at Doncaster today.
They are a point above the Seagulls with an identical plus 14 goal difference ahead of their final game at home to promoted Burnley next Saturday.
Albion's last day hosts Nottingham Forest are out of contention after crashing 4-1 at Bournemouth.
Watford, beaten 4-2 at Derby, have also dropped out of the race and so almost certainly have Blackburn, despite winning 3-1 at Charlton.
Wigan are looking nervously over their shoulders after losing 2-0 at home to Blackpool.
They have dropped below Reading into sixth and are one point above Albion with a one-goal inferior goal difference.
Wigan have a game in hand at relegation-haunted Birmingham on Tuesday evening before visiting Blackburn on the last day.
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