Albion fell to a 2-1 defeat at Bournemouth in the Premier League this evening. Here's six things we learned from the game.
After a close first half, Albion will feel it is an opportunity missed not to be returning back down the south coast with three points.
Solly March's header gave them the lead ten minutes into the second half but Jordon Ibe's introduction changed the game and he set up goals for Andrew Surman and Jermain Defoe as Bournemouth claimed a 2-1 win.
It's a harsh reality of how tough the Premier League will be this season. Brighton will look back on the goals they conceded and know they could have done better with both.
In the Championship last season, Albion would have probably returned home with all three points after a performance like that. There were positives to take and there's no need for the Seagulls to be too downbeat - after all Bournemouth finished ninth last season.
It's going to be home form which will ultimately decide if Albion stay up or not, however they will need to pick up the odd point or two on the road and they will feel disappointed not to have picked up anything tonight.
Bournemouth sent on Jordon Ibe after 65 minutes and the former Liverpool winger set up two goals in the space of six minutes.
Albion had looked solid at the back until they gave the ball away and Andrew Surman latched on to Ibe's pass, side-stepped Lewis Dunk's challenge and side-footed home into the bottom corner on 67 minutes.
Ibe then had a goalbound effort deflected over by Dunk, before he set up Jerman Defoe for his first Bournemouth goal since returning to the club in the summer after 73 minutes.
The England international had scored just once in his previous 17 Premier League games but fired home low into the far corner - although Albion will again be disappointed they did not do more to stop the ball getting to Defoe.
Solly March's impressive start to life in the Premier League continued with his first goal in the top flight.
The talented young English winger had been a constant threat to opposition defenders in Albion's opening four Premier League games and helped set up the Seagulls' opener against West Brom last week.
Tonight he found the back of the net with, perhaps surprisingly, a header. The youngster from Hailsham leapt highest to meet Pascal Gross' right-wing cross and head past Cherries keeper Asmir Begovic ten minutes into the second half.
If March continues this impressive form, he'll do his hopes of an England international call in the future no harm at all.
How's your luck?
Albion's luck was out early in the second half when they went close to opening the scoring three times in the space of a minute.
The Seagulls did not have a touch inside the Bournemouth penalty area in the first half but that all changed in the opening six minutes of the second period.
Shane Duffy and Davy Propper both had headers cleared off the line by Andrew Surman, before Dale Stephens headed Duffy's knock-down against the underside of the bar from four yards out moments later.
Brighton's lively start to the second half was rewarded on 55 minutes when Pascal Gross did superbly down the right and his cross was headed home by Solly March from six yards.
Albion were unable to hold on, though, as the Cherries hit back to claim all three points.
Sussex born Steve Cook, who started his career with Albion, missed out on a reunion against his former side owing to injury.
The 26-year-old from Hastings played seven matches for Brighton before joining the Cherries in October, 2011. He has since helped Bournemouth reach the top flight of English football and become a regular in the Premier League.
His absence saw Simon Francis start in central defence alongside Nathan Ake, who was named man of the match after an impressive display.
There was also a return to the Vitality Stadium for Albion striker Glenn Murray. The 33-year-old scored four goals in 22 matches for Bournemouth, before joining the Seagulls, initially on loan last summer before making the move permanent in January.
He came on for the 13 minutes with Brighton chasing the game but the Seagulls failed to create any clear chances to equalise as they slipped to a third league defeat of the season.
We've come a long way
Ten years ago, the two sides were going head to head in League One and tonight they battled it out in the top flight of English football.
In the 2007/08 season, Albion finished seventh in the third tier, while the Cherries were relegated into League Two after a ten point deduction saw them finish fourth from bottom.
Bournemouth have since climbed the divisions and this is now their third season in the Premier League, while Brighton were promoted from the Championship last year after winning League One in 2010/11.
A tweet from Sky Sports prior to kick-off showed just how much life has changed at both clubs since their League One days.
Back in 2007/08, Bournemouth's record transfer fee paid was £250,000, while Brighton's was reported as £300,000. This summer, the Cherries bought Chelsea defender Nathan Ake for a reported £20m fee and the Seagulls paid a figure believed to be £16m for winger Jose Izquierdo from Club Brugge.
Bournemouth's record transfer fee received has also risen from £800,000 to £12m and Albion's has climbed from £1.5m to £8m in the past ten years.