Gifton Noel-Williams took just 18 minutes to find the net on his debut but a fortuitous equaliser earned Luton a point in atrocious conditions at the Withdean.
Noel-Williams, who arrived on the south coast only on Thursday following his deadline-day loan switch from Burnley, showed what Brighton have been missing all season with an all-action performance up front capped by a fine header.
But the Hatters nudged their hosts a step closer to relegation when they levelled just after the hour with a bizarre goal accredited to Steve Robinson.
Brighton now find themselves nine points adrift of safety and preparing for life back in League One following a two-year stint in the Coca-Cola Championship.
Brighton's gameplan soon became apparent with ball after ball aimed towards Noel-Williams as the rain lashed down, rapidly turning the Withdean pitch into a mudbath.
And the tactic almost worked in the opening moments when the new boy fed Alex Frutos, forcing Marlon Beresford to race out of his goal to clear.
But Luton, who are still in with a slim chance of a play-off place, looked the more dangerous in attack early on and Steve Howard fizzed a low drive across the face of goal before Warren Feeney headed a Sol Davis cross wide.
The hosts had a shout for a penalty turned down when Noel-Williams and Chris Coyne hit the deck together, but referee Paul Armstrong waved away the appeals.
But Noel-Williams did put the Seagulls ahead with a superb glancing header from Adam Hinshelwood's right-wing cross which gave Beresford no chance.
Howard should have dragged Luton level moments later, but the striker scuffed his first-time shot in front of goal.
Seagulls veteran Guy Butters planted a free header over the top from Richard Carpenter's corner, while at the other end fit-again defender Markus Heikkinen forced a smart save from Wayne Henderson with a low drive.
Hinshelwood produced a superb goal-saving challenge on Feeney in the area as the second half got under way with surface water beginning to appear on the Withdean pitch.
Feeney had latched on to Carlos Edwards' header and was shaping to shoot when the young defender whipped the ball away.
Frutos looped a volley over the bar before Beresford kept Luton in the game with a fine save from Dean Hammond.
And moments later the visitors were level when Feeney drove in a low cross which Henderson palmed to the feet of Robinson.
The ball agonisingly rebounded in off a messy combination of Robinson's shins and those of Albion defender Paul McShane as he attempted to clear.
Gary Hart thought he had put the hosts back in front midway through the second half, but his curling effort cannoned off Beresford's left-hand post, and Noel-Williams hit the side-netting as his new side poured forward in the mud.
But Luton survived the late onslaught and could have snatched victory themselves near the end when sub Rowan Vine hooked the ball over the top.
Teams:
Brighton Henderson, Hinshelwood, Butters, McShane, Lynch,Hart (Carole 90), Carpenter, Hammond, Frutos (El-Abd 62),Noel-Williams, Kazim-Richards (Gatting 73).
Subs Not Used: Dodd, Chaigneau.
Booked: Kazim-Richards.
Goals: Noel-Williams 18.
Luton Beresford, Foley, Heikkinen, Coyne, Underwood,Edwards (Bell 64), Davis, Robinson, Brkovic (Vine 65), Howard,Feeney (Showunmi 75).
Subs Not Used: Perrett, Brill.
Booked: Davis.
Goals: Robinson 61.
Att: 7,139
Ref: P Armstrong (Berkshire).