LONDON (AFP) - Portsmouth's 69-year wait for a major match at Wembley will finally come to an end when the last Premier League side left in this season's competition faces West Bromwich Albion in the semi-finals of the FA Cup here on Saturday.

Following their dramatic 1-0 win over Manchester United in the quarter-finals there is no doubt that Harry Redknapp's side will start as favourites against the Baggies, who are pushing for promotion from the second-tier Championship.

But Pompey fans know all about how an underdog can triumph at Wembley. When they won the FA Cup for the only time in their history, in 1939, their opponents, Wolverhampton Wanderers, were hot favourites.

Pompey though won 4-1 and the south coast club then kept the Cup for seven years because of the Second World War.

In the years after the conflict, Portsmouth were twice champions of England but then suffered a long and steady decline which took them into the then Fourth Division (now League Two).

However, after decades of mediocrity, the club is now enjoying its best season for half a century and lies sixth in the Premier League table.

But what the Fratton Park faithful really crave is a trophy and the FA Cup, one of the few prizes on offer which a club outside the 'Big Four' of Arsenal, Chelsea, Liverpool and Manchester United, who between them have monopolised the Cup for 13 years, have a chance of winning, would do nicely.

Portsmouth though will once again have to make do without in-form striker Jermain Defoe, who has scored eight goals in seven games, because the former Tottenham forward is cup-tied.

But midfielders Niko Kranjcar, Papa Bouba Diop and Sulley Muntari, their spot-kick hero at Old Trafford, will look to pose problems for the Baggies defence along with forwards John Utaka and Nwanko Kanu, who moved to Pompey from West Brom four years ago.

Portsmouth manager Harry Redknapp's ability to get the best out of players nearing the final stages of their careers is evident in Portsmouth's defence where the England duo of goalkeeper David James and centre-back Sol Campbell have both been key figures this season.

"We are in a semi-final and it is fantastic. It is a massive cup and we have a great opportunity to win it," said Campbell, whose side, should they win this weekend, will face the winners of Sunday's all-Championship semi-final between Barnsley and Cardiff.

There is also a strong sense within the squad of wanting to win the Cup for 'Harry'. His skills in the transfer market and his East End of London background have led Redknapp to be portrayed as a 'wheeler-dealer.'

This, however, has tended to overshadow his tactical ability and man-management skills and now he has the chance to guide a team to the silverware his admirers believe the former West Ham boss deserves.

"Harry, for me, is fantastic," said Campbell. "He wants to win and play football, that's the main thing. He has bought well - proper players - and got people relaxed and playing well.

There was talk of Harry going to (manage) England, and I think that is enough, really.

"A lot of people understand that he has got different ways, but he gets results. He gets players playing. It's good."

West Brom are the top scorers in this season's FA Cup but they have yet to face a Premier League side in their run to the last four.

Tony Mowbray's men are regarded as the best 'footballing' side in the Championship and while promotion to the top flight remains the priority, hopes the West Midlands club's fans have every reason to think that, after a season of Cup upsets, their side could lift the trophy for the first time since 1968.

Veteran striker Kevin Phillips has plenty of big-match experience and midfielder Jonathan Greening once played for Manchester United.

"We know that if we play to our potential we can make life very difficult for them," said Mowbray. "Hopefully we will do that and give a really good account of ourselves."