Albion squeezed through to the Southern Section semi finals of the Johnstone's Paint Trophy against all the odds.

Experienced substitute Kerry Mayo emerged as the unlikely hero in a penalty shoot-out, forced by an 88th minute equaliser from Jake Robinson.

Mayo showed nerves of steel after Zak Whitbread blazed over from the spot for Millwall to seal a remarkable victory for the Seagulls.

Albion had twice spurned the opportunity to get their noses in front in the shoot-out, when Dean Cox and substitute Joe Gatting saw their efforts saved by Chris Day.

Darren Byfield had missed the target with Millwall's first penalty and their fourth, taken by on-loan Tottenham midfielder Charlie Lee, had been kept out by Wayne Henderson.

But the Seagulls refused to be denied, Mayo adding to successful spot-kicks by skipper Dean Hammond and 11-goal Robinson.

They showed extraordinary resilience and spirit following a straight red card in the 21st minute for Guy Butters for a foul on Ben May just outside the box.

As if playing with ten men was not enough of a challenge, they also had Adam El-Abd stretchered off midway through the second half with a deep cut to his calf.

It seemed as if it just was not going to be their night until Robinson struck and Mayo moved into the spotlight to take Dean Wilkins' side a step closer to a big day out at the new Wembley or the Millennium Stadium.

Wilkins named the same side for the third match in succession, resisting the temptation to tinker following consecutive 1-0 defeats against Tranmere and Doncaster.

Milton Keynes Dons, the Seagulls' victims in the previous round, treated the competition with disdain but Millwall were more or less at full strength.

Frenchman Zoumana Bakayogo, who was on trial with Albion during pre-season, started at leftback after coming off the bench in last Saturday's 3-1 defeat at League One leaders Nottingham Forest.

The inquest into the Doncaster setback centred around Albion's habitual slow starts to matches. They were determined to be quicker out of the blocks this time and could easily have gone ahead early on.

In the third minute a free-kick by Joel Lynch found Tommy Fraser unmarked beyond the far post. His header from ten yards out was blocked behind by Whitbread but Fraser should have at least tested Chris Day in the Millwall goal.

A similar opportunity arose from Lynch's resulting corner. This time it was Adam El-Abd in space on the edge of the six-yard box but he mistimed his header high and wide.

Day was forced into meaningful action just 11 minutes into the contest when a high cross by Robinson was neatly controlled by Cox on the fringes of the area. The diminutive playmaker's well-struck shot was parried for a corner by the diving Day.

Albion were rocked back on their heels after their encouraging opening when Butters was sent off in the 21st minute.

The veteran central defender tried to cover when a header by Darren Byfield released his strike partner May.

Butters brought down May a yard outside the box and, as the last man, he received a straight red card from referee Paul Armstrong.

It was a galling case of deja vu for Albion. Richard Carpenter was sent off in the first half in the League visit to Millwall in September, when Albion went on to win 1-0 in Wilkins' first match in charge.

They had even longer to cope with a numerical disadvantage on this occasion but at least they were not doubly punished from the free-kick arising from Butters' unfortunate dismissal, Chris Hackett's effort deflecting wide via a team-mate.

Albion adjusted by dropping El-Abd back from his role as midfield enforcer into the heart of the defence alongside Adam Hinshelwood.

The pattern of the game was altered by Butters' absence, Millwall becoming more of an attacking threat as the half wore on.

Wayne Henderson produced a brave block at close quarters when Byfield got a toe to a near-post cross by Hackett.

Albion's Republic of Ireland international keeper also had to scoop away an angled drive by Hackett after Lee, on loan to Millwall from Spurs, had driven narrowly over the bar from 25 yards.

Henderson was at fault when the Lions made the breakthrough four minutes from the break, although he had some justification for claiming he was impeded as he tried to clear Hackett's corner when surrounded by a cluster of bodies.

The ball broke from the melee for Paul Robinson, the Millwall captain, to nod in from point blank range.

Cox was hurt in the incident and required treatment inside the Albion net before he was able to continue.

It was an untidy way for Albion to fall behind and their deficit nearly doubled moments before the interval when May's header at the far post from another corner by Hackett was blocked by a combination of Henderson and Cox.

Millwall did not demonstrate any great desire to press home their advantage after the break, although a long ball through the inside right channel by Robinson freed Byfield for a shot which Henderson saved with relative comfort at his near post.

Albion looked quite dangerous on the counter-attack, unsettling the home side sufficiently to suggest an equaliser was not beyond them even in such adverse circumstances.

In the 63rd minute Andrew Whing fed Robinson for an angled shot which Day gathered at the second attempt, with Alex Revell lurking to pick up the pieces.

Albion's misfortune continued three minutes later when El-Abd was stretchered off after a typically determined tackle to block a shot inside his own area.

Alistair John, the 18-year-old winger on loan from Charlton, took his place as the Seagulls were forced into further amendments, Whing switching to a back three also comprising Hinshelwood and Lynch.

Further changes were made in search of salvation, Mayo entering the fray for the perpetually substituted Fraser and Gatting replacing the leg-weary Revell upfront.

Albion would surely have been awarded a penalty themselves if John had gone down under a challenge from Whitebread, rather than staying on his feet during a tricky surge into the Millwall box.

They also had appeals for a spot-kick denied by Armstrong seven minutes from time when Robinson went down under a challenge from his Millwall namesake as he tried to latch on to Gatting's header from a long clearance by Henderson.

Albion's topscorer got his own back in the 88th minute with the equaliser they deserved, particularly for the way they performed with ten men.

Cox found Robinson with a raking, crossfield pass and his fierce shot from a tight angle fizzed in via a defender.

ALBION (4-4-2): Wayne Henderson; Andrew Whing, Adam Hinshelwood, Guy Butters, Joel Lynch; Tommy Fraser, Adam El-Abd, Dean Hammond, Dean Cox; Alex Revell, Jake Robinson. Subs: Michel Kuipers, Kerry Mayo for Fraser (withdrawn, 71), Joe Gatting for Revell (withdrawn, 74), Tommy Elphick, Alistair John for El-Abd (injured, 66).

MILLWALL (4-4-2): Chris Day; Mark Phillips, Paul Robinson, Zak Whitbreak, Zoumana Bakayogo; Chris Hackett, Charlie Lee, Marvin Elliott, Gavin Grant; Ben May, Darren Byfield. Subs: Lenny Pidgeley, Danny Senda for Grant (withdrawn, 64), Liam Trotter for Elliott (injured, 43), Chris Zebroski for Bakayogo (withdrawn, 46), Poul Hubertz.