Albion head into Saturday's home game against Ipswich Town with the best defence in the Championship.
The Seagulls and Queens Park Rangers had conceded 28 goals apiece before ten-men Rangers' 3-0 defeat at Sheffield Wednesday tonight.
Harry Redknapp's side, beaten 2-0 at the Amex last Tuesday, fell behind Albion in the mean league when Richard Dunne was sent-off at Hillsborough conceding a first half penalty which Wednesday converted.
Leon Best and Lewis Buxton scored further goals for the Yorkshiremen after the break.
Rangers remain seven points clear of Albion but have now played a game more.
Albion go to Hillsborough next Tuesday.
The Seagulls' challenge for the play-offs received a further boost as Wigan were held 3-3 at home by Yeovil in their game in hand. They are only three points clear of Oscar Garcia's side.
Charlton, visitors to the Amex on April 12, snatched a late winner at home to Bournemouth to ease their relegation worries.