Millwall have reached the FA Cup final for the first time in their 119-year history after they beat first division rivals Sunderland 1-0 in their semi-final at Old Trafford.
Australian Tim Cahill's 26th-minute goal on Sunday set up a meeting with 10-times winners Manchester United in the final and it also earned the south London club a place in next season's UEFA Cup for the first time thanks to United's qualification for the Champions League through their league placing.
Sunderland had their chances but finished with 10 men after Jason McAteer was sent off four minutes from time as Dennis Wise's team became the first club from outside the top flight to reach the FA Cup final since Sunderland in 1992.
United beat holders Arsenal 1-0 in the other semi-final at Villa Park on Saturday and will start strong favourites at Cardiff's Millennium Stadium on May 22.
In that match Millwall player-manager Wise will be aiming to become the first man to win the Cup with three different clubs, having played in the Wimbledon team that shocked Liverpool in 1988 and then for Chelsea who beat Aston Villa in 2000.
FIGHTING SPIRIT
The 37-year-old's enthusiasm and fighting spirit have epitomised Millwall's effort throughout the competition, though they also had the luck of not having to face a top flight side in any round - something not done since Bolton Wanderers reached the final 51 years ago.
Sunday's match was Millwall's first appearance in the last four since 1937, when, as a third division club, they lost to Sunderland.
It was the north-east club who started the stronger at Old Trafford and they almost took the lead after seven minutes when the lively John Oster curled a free-kick against the underside of the crossbar.
Oster and McAteer both shot wide but Millwall got the all-important goal when Cahill struck a well-controlled volley from 10 yards after Sunderland goalkeeper Mart Poom had saved from Paul Ifill.
Sunderland dominated the second half, having been kept in the tie by Poom's fine save from former Sunderland striker Danny Dichio.
Sunderland striker Kevin Kyle twice went close before being surprisingly substituted by Mick McCarthy, a former Millwall player and manager, but the best chances fell to Julio Arca and then McCartney, who both failed to hit the target.
Despite their possession, Sunderland were generally short of creativity and their frustration was summed up when McAteer was given his second yellow for a needless push on the halfway line.
Both teams now return to the job of trying to earn promotion to the English premier league.
Millwall play Cardiff on Wednesday but it is the fairytale trip to the Welsh capital next month that will occupy the minds of the fans returning to London on Sunday.