Albion stormed through to the second round of the FA Cup for only the second time in seven seasons at Withdean last night.
Goals by captain Paul Rogers, Paul Watson and late substitute Kerry Mayo clinched a trip to Plymouth a week on Saturday.
Watson was the provider for the first goal. Rogers converted his cross after nine minutes, his third goal of the season.
Watson's inswinging corner on 64 minutes then caught everybody by surprise in a packed six-yard box to make it 2-0.
Mayo rounded off a resounding triumph two minutes from time.
Mark Walton was outstanding for Micky Adams' men
The only change made by Albion was on the bench, goalkeeper Ormerod replacing Paul Armstrong.
Peterborough brought in midfielder Gill at the expense of player-coach Steve Castle.
The fans certainly responded to Adams' plea to get behind the team, making plenty of noise in the early stages.
Shields was booked on six minutes by Premiership referee Neal Barry for not retreating when Albion were awarded a free-kick deep inside their own half.
The Seagulls got just the start they wanted with a goal three minutes later.
Rogers, arriving late inside the area, was unmarked as he met Watson's cross from the right with a shot into the ground which bounced into the roof of the net.
It was a good omen, since the skipper's previous two goals both resulted in wins against Leyton Orient and Cheltenham.
Nothing was seen of Peterborough until Etherington and Davies, the subject of a rejected £3million double bid from Aston Villa, combined in the 19th minute.
Etherington's free-kick was headed by Campbell straight to the feet of Davies, whose shot from 20 yards flashed wide.
Walton, fresh from three clean sheets in the last five games, produced a double save to preserve Albion's lead.
The big Welshman parried Etherington's angled drive after the Peterborough winger outpaced Watson, then he got a hand to Clarke's attempted flick.
The visitors were awarded an indirect free-kick in a dangerous position on the lefthand edge of Albion's area when Campbell was penalised for obstructing Forinton. Etherington completely wasted it with an aimless effort well wide of the target.
Walton made another fine stop just past the half-hour, deflecting behind a downward header from Edwards when the Peterborough captain was unmarked at the far post from a Davies corner.
Barry Fry's young side were looking quite dangerous, but Albion almost doubled their advantage in the 34th minute.
Cullip's cross hit Hart on the back before falling for Aspinall to strike a low shot which was deflected narrowly wide for a corner.
Another half-chance came Albion's way just before the break, but Watson's attempted curler went well wide of the far post.
A long ball forward from Wicks six minutes into the second half caught the Albion defence sleeping.
Walton was a bit slow off his line and he was slightly fortunate to block Forinton's touch.
The glove-clad Cla0rke, who opened the scoring in spectacular fashion in the first game between the teams at London Road, back-headed on to the roof of the net from a Davies centre as Posh pressed in search of an equaliser.
Forinton was next to threaten for the visitors.
The striker, with five goals in six games since his £250,000 move from Birmingham, made room for himself to unleash a low shot from the edge of the box which Walton again did well to stop.
Walton was having a fine game, as was Carr at the heart of the defence. The big stopper, making only his fifth appearance since his £25,000 summer switch from Gillingham, got in several telling challenges.
On the hour mark Etherington tried to leap a shot over Walton from 20 yards, but the keeper was alert to the situation and made a comfortable catch.
Peterborough, well on top since half time, came close again shortly after, Forinton getting the better of McPherson to flash an effort across the face of goal.
Adams decided a change was necessary, so the muscular Cameron replaced Thomas on 62 minutes.
CaMERON gave Albion the breathing space they needed two minutes later. He got his head to Watson's inswinging corner in a heavily-congested six-yard box.
It was yet another example of the Seagulls' expertise from set pieces.
Walton continued to keep Posh at bay, smothering a shot from Clarke, which was then cleared for a corner.
Clarke headed over a right wing centre from Hooper with 20 minutes left as Peterborough desperately try to claw their way back.
Mayo, on as an 86th minute substitute for Aspinall, scored the third two minutes later after Oatway put him clean through.
Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.
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