United earned their place in the last four for the fourth time in five seasons with a 2-1 success over Chelsea - who ended the match with 10-men after Ramires was sent-off in the second-half - and a 3-1 triumph on aggregate which will heap the pressure on the losers'' manager Carlo Ancelotti.
United - whose goals came from Javier Hernandez and Korean Park Ji-Sung - will play either Schalke 04 or holders Inter Milan, with the Italian side requiring a miracle in Germany today as they trail 5-2.
Barcelona - reaching the semi-finals for a record fourth successive time - inflicted the first home defeat in European competition on 2009 UEFA Cup winners Shakhtar since they lost to Sporting Lisbon in October, 2008 as Lionel Messi scored the only goal of the game to seal a 6-1 aggregate victory yesterday.
Messi''s goal, his 48th of the campaign and yet another landmark for the two-time world player of the year as it is a club record for a season, sets them up for a likely semi-final with bitter domestic rivals Real Madrid, who take a 4-0 lead to Spurs in today's second leg clash.
Ancelotti had got the better of Ferguson and United twice before in the competition when in charge of AC Milan but apart from the opening 25 minutes there was little to suggest he would make it three.
Ferguson believes that United's form is an ominous sign for their opponents as they attempt to do the treble of the league title, FA Cup and Champions League.
"You can see the momentum that this team is building up at the moment," said the 69-year-old Scot.
"I think we've hit our form. The two matches against Chelsea and the league win over West Ham (a 4-2 win) shows that."
Ancelotti was gracious in a defeat that all but ensures barring a miraculous run of results in the league they will finish trophyless this season - not something Russian owner Roman Abramovich will appreciate.
"We had good control of the game in the first 25 minutes but failed to take our chances," admitted Ancelotti.
"We have to move on from this and ensure we finish in the top four (a Champions League spot)."
Ancelotti's decision to start with the misfiring Fernando Torres was an abject failure as the Spanish striker spent more time arguing with the referee than in the opponent's penalty area and is now 11 hours without a goal since signing from Liverpool.