Jack Grealish's late goal denied Brighton the title as David Stockdale's mistake handed the Sky Bet Championship crown to Newcastle.
The goalkeeper failed to deal with Grealish's 89th-minute effort as the Seagulls were held to a 1-1 draw by 10-man Aston Villa.
Newcastle beat Barnsley 3-0 to take the title by a point despite Glenn Murray's second-half penalty putting Brighton on the brink at Villa Park.
Nathan Baker was sent off after bringing down Sam Baldock for the spot kick but Brighton could not capitalise.
The Seagulls were already promoted, ending a 34-year top-flight exile, and victory would have seen them go up as champions but they lacked urgency and rhythm for long spells.
Brighton & Hove Albion
