London: Some still sniffily dismiss Chelsea as arriviste upstarts but by becoming the seventh club to complete the Double on Saturday they would take another solid step in establishing themselves as real soccer heavyweights.
Having won the Premier League title in scintillating style with an 8-0 thrashing of Wigan Athletic last week Chelsea go into the FA Cup final as overwhelming favourites to beat bottom club Portsmouth at Wembley.
Preston North End, Aston Villa, Tottenham Hotspur, Arsenal (three times), Liverpool and Manchester United (three times) are the only other clubs to have won the two biggest domestic honours in the same season in England.
Even Liverpool fans, whose Double came 24 years ago and last league title four years later, might then have to ditch the "you`ve got no history" chant they throw at the Londoners.
Chelsea are also bidding to become the sixth club to retain the trophy following their victory over Everton last season while Portsmouth can make their own special mark by becoming the first relegated club to win the Cup - four others have reached the final, most recently Middlesbrough in 1997.
Although they had won domestic and European honours in days gone by, it is only since Roman Abramovich`s 2003 takeover that Chelsea have consistently gone toe to toe with the big boys.
Three Premier League titles, two FA Cups, two League Cups and a host of Champions League near-misses have come under Abramovich - albeit via various managers - and now another satisfying and all-too-rare achievement is there for the taking.
Doing the Double would also mark a terrific first season in English football for manager Carlo Ancelotti, whose Champions League failure can be put on the back burner while everyone enjoys another big day out.
"If we were to do the Double it would be a fantastic first season," said Ancelotti, who said he had really enjoyed the atmosphere at English grounds and is in for a treat at Wembley.
The Cup is always capable of throwing up surprises but it would count as one of the all-time upsets in Chelsea were to lose.
Since Portsmouth`s arrival in the Premier League seven years ago Chelsea have won 13 and drawn one of their 14 meetings and the last was a 5-0 thrashing at Fratton Park in March.
"We have an agreement that they will stop at four," said Portsmouth and former Chelsea manager Avram Grant this week.
"I don`t believe in football that you should have fear but I believe against this team we need to be very careful because they can hurt you from everywhere. They are a very good team.”
"The whole league is between us. I know we are underdogs but it`s 11 versus 11 and we will try to play football."
Portsmouth really do have nothing to lose.
Relegated after finishing a distant bottom, in administration with debts of over 130 million pounds (USD 194.2 million), Wembley will be a much-needed distraction and financial shot in the arm.
"When I went to Chelsea I don`t think anybody would bet one pound that we would be in the Champions League final but when I came here I don`t think anybody would have put one penny on us being in the FA Cup final," said Grant.
"It`s a big achievement. After the quarter-final we knew we would be at Wembley and the fans stayed one hour after the game they were so happy. Then, we thought we had done more than our job.”
"Even if we win the final it would be hard to be more happy than we were in the semi-final. It was a great feeling. Now to play against Chelsea, I honestly don`t care."
The fans certainly enjoyed it two years ago when Portsmouth beat Cardiff City to win the Cup but though through the subsequent fire-sale only four of the team from that day are still at the club, the supporters have remained loud and proud.
"The fans have been great. Everybody needs to learn from them about how to support the team," said Grant. "They are a big big part of the achievement. The players have been great but the fans have been unbelievable."
Another landmark is in sight on Saturday as Chelsea fullback Ashley Cole can become the first player to win the Cup six times having triumphed three times with Arsenal and twice with Chelsea.
The only two other players to have collected five winners medals did so in the 19th century.