The classic game of two halves saw Millwall come from behind to claim an unlikely victory and boost their Coca-Cola Championship survival hopes.

Dean Hammond's early goal gave Brighton a deserved half-time lead, but a Millwall side who had been out-fought and out-thought for the opening 45 minutes came out after the break a totally different side.

In truth, three of them were different after desperate boss David Tuttle made a triple substitution including young forward Josh Simpson, who grabbed the winner just three minutes after Ben May's equaliser.

The basement boys from south London went in to the game knowing defeat would leave them nine points behind fourth-bottom Brighton and staring the drop to League One in the face.

Instead the Seagulls were left to rue a host of missed first-half chances following a result that keeps them entrenched in the relegation dog-fight.

It all looked so different in the third minute, the Seagulls stunning the visitors when Hammond powerfully nodded home Alexandre Frutos' free-kick at the far post for his fourth goal of the season.

Brighton were stifling the visitors in midfield to the obvious frustration of Lions skipper David Livermore, who was lucky to escape with a 12th-minute booking for a rash two-footed challenge on Richard Carpenter.

Another dangerous Frutos free-kick was then flicked on by former Lions forward Mark McCammon but Hammond could only head straight at Colin Doyle, before the move of the half almost culminated in the Seagulls' second.

Frutos played a neat one-two with Colin Kazim-Richards before whipping in a curling cross that eluded the onrushing McCammon's outstretched leg by inches.

Hammond should have doubled their advantage as the interval approached, but aimed his shot too close to Doyle after being played in by McCammon.

And the hosts were given a warning when a rare Millwall attack saw Kevin Braniff's header ruled out for a push just before the break.

Tuttle, who played under opposite number Mark McGhee at Millwall, responded with by throwing on Simpson, Marvin Williams and Barry Cogan, and was immediately rewarded with an equaliser.

Alan Dunne charged down the right, cut inside and found May on the edge of the six-yard box who had the simple task of firing past the helpless Michel Kuipers after 47 minutes.

And three minutes later the visitors went ahead when Brighton failed to clear Jody Morris' cross, allowing Simpson to turn and fire home his first goal of the season.

Simpson was denied a second when, with the hosts in disarray at the back, Kuipers finger-tipped his shot over the crossbar.

McGhee threw on Leon Knight, who had been consigned to the bench once again, and the diminutive forward squandered a glorious chance to level five minutes from time.

McCammon headed the ball down into Knight's path, but the former Chelsea trainee could only blast the ball high over the crossbar.

And in injury-time a McCammon header was somehow scrambled over the top by Doyle as Millwall held out.

Teams

Brighton Kuipers, Reid, Butters, McShane, El-Abd, Carole, Hammond, Carpenter, Frutos, McCammon, Kazim-Richards (Knight 68).

Subs Not Used: Mayo, Robinson, Tommy Elphick, Chaigneau.

Booked: McShane, McCammon.

Goals: Hammond 3.

Millwall Doyle, Robinson, Lawrence, Whitbread (Cogan 45), Craig, Dunne, Morris, Livermore, Braniff (Simpson 46), May, Dyer (Williams 45).

Subs Not Used: Phillips, Hendry.

Booked: Livermore, Williams, Cogan.

Goals: May 46, Simpson 50.

Att: 6,847

Ref: M Thorpe (Suffolk).