Josh Brownhill's solitary goal two minutes before half-time dampened the carnival atmosphere with a 1-0 for the visitors as Albion were denied lifting the title in front of their own fans.
Victory would have seen that and with it being the Seagulls' first home game again since clinching promotion to the Premier League against Wigan, their was a carnival atmosphere ahead of kick-off.
A record crowd of 30,338 were treated to pre-match entertainment, but City were the ones celebrating at full-time as the points secured their safety in the division.
Albion meanwhile will have to win at Aston Villa next Sunday to guarantee the title with second-placed Newcastle, who are one point behind with a better goal difference, at home to Barnsley.
Chris Hughton rung the changes, making five from the side that sunk to a disappointing 2-0 defeat at Norwich last Friday. Gaetan Bong, Dale Stephens, Beram Kayal, Jiri Skalak and Tomer Hemed replaced Seb Pocognoli, Steve Sidwell, Oliver Norwood, Solly March and Jamie Murphy.
It was a party atmosphere ahead of kick-off in the Amex and streamers and balloons were still falling from the stands when, after just three minutes, Glenn Murray scuffed his shot across goal and wide.
It was a fairly damp squib after that for much of the first half, the ball was given away often by both sides and City had little to trouble David Stockdale in the Albion goal.
Murray profited from a full-blooded tackle with Josh Brownhill in the 34th minute as it looked as though the striker had over-run the ball, but Murray won it and slid in Bruno on the right, but his cross was punched away by Frank Fielding.
Knockaert - becoming increasingly frustrated after feeling he was on the end of some rough justice after tackles - showed some magic on the left to beat his man and feed Bong, but Murray headed the full-back's dangerous cross down in the box rather than at goal and it rolled clear.
Despite those chances it was the visitors that led two minutes before half-time as Brownhill headed a low right-wing cross past Stockdale from seven yards.Solly March was given the nod at half-time as he replaced Skalak on the left-wing.
And it was the local youngster's corner that almost got Albion level seven minutes into the second half, but Uwe Huenemeier's diving header flew just wide of the post.
The visitors almost added a second on the hour mark as Joe Bryan's header from outside the box following a corner was swung at by Matty Taylor, but he couldn't conect when six-yards out.
Albion failed to increase the tempo as Steve Sidwell came off the bench and a teasing Murray cross on 74 minutes evaded everyone as it flashed across the box. Dunk - up for a corner that was only half cleared - then dragged across the goal and wide with eight minutes left to play.
The hosts tried in vein to get level as March cut in and fired over, while at the other end a strong Stockdale hand pushed away Bobby Reid's effort on the counter.
And that was that, Albion enjoyed a post-match lap of hour, but it was far from the party that the home side were hoping for.
Brighton: Stockdale; Bruno, Huenemeier, Dunk (Tomori 89), Bong; Knockaert, Stephens, Kayal (Sidwell 62), Skalak (March 46); Murray, Hemed. Unused subs: Maenpaa, Rosenior, Murphy, Akpom.
Bristol: Fielding, Little, Flint, Wright, Bryan, Brownhill, K.Smith, Pack, Paterson (O'Dowda 89), Abraham (Djuric 81), Taylor (Reid 77). Unsued subs: Giefer, Magnusson, Hegeler, Tomlin.Referee: Oliver Langford.