Chris Hughton's side have 86 points from 41 games, two more than Newcastle, who visit sixth-placed Sheffield Wednesday on Saturday, and 12 clear of Huddersfield Town in third.
Brighton need a maximum of 10 points from their final five games to return to the top tier for the first time since 1983.
Glenn Murray scored the opener when he was released through the middle after 58 minutes before Sebastien Pocognoli scored with a superb free-kick from outside the area six minutes later, his first goal for seven years.
Matt Smith replied with a 74th-minute header for Rangers, who had midfielder Ravel Morrison starting his first game since Nov. 2015 when he appeared for Lazio.
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(Reporting by Neil Robinson; Editing by Ken Ferris)
