Rafael Benitez's team booked a semifinal clash against Manchester City after overcoming the runaway league leader over two legs.
Another key moment for the Blues was a stunning save of the season contender from Petr Cech that denied Javier Hernandez an equalizer midway through the second half.
This Bank Holiday replay, coming just 48 hours after both clubs were involved in away league fixtures, did not come to life until the second half but there was plenty of drama to overshadow handshake-gate involving the two managers and the saga of the returning Rio Ferdinand.
Juan Mata was the architect of Chelsea’s comeback in the first leg at Old Trafford and he was equally influential on home turf, with his most notable contribution the delicious chipped pass that set up Ba for the game's only goal. The FA Cup holder did not score the second goal that the team's dominance merited but still booked a date with Man City at Wembley on April 14 to keep alive the club's hopes of defending its crown.
As expected, both managers made wholesale changes to the teams that started in league clashes less than 48 hours previously.
Sir Alex trumped Benitez in the rotation stakes by bringing in seven new players to the Chelsea manager’s six, although Wayne Rooney was surprisingly not one of them. The forward was omitted from the United matchday squad for the second consecutive match with what Sir Alex claimed was a groin injury picked up on England duty. David De Gea, Chris Smalling, Michael Carrick and Antonio Valencia were the only United players to start both Saturday’s 1-0 win at Sunderland and then again today.
Benitez notably dropped John Terry, Frank Lampard and Fernando Torres to the bench as he significantly reshuffled his attacking options, with Ramires, Juan Mata, Eden Hazard and Demba Ba restored to the team, along with David Luiz and Ashley Cole.
Before the match began, there was the chance for both sets of supporters to vent their feelings towards Ferdinand, returning to the pitch for the first time since his withdrawal from England’s World Cup qualifiers.
The defender was roundly jeered by the home fans at the end of the warmups, again when the teams were read out shortly before kickoff and then whenever he touched the ball as the match began. The large United contingent responded on nearly every occasion with chants of ‘Rio, Rio, Rio’.
Ferguson sprung a tactical surprise with Phil Jones anchoring alongside Carrick, Tom Cleverely tucked in on the left of midfield and Antonio Valencia deployed at right back with Nani in front of him.
Even without Jones providing extra screening, Benitez had warned that it simply would not be possible to have a classic because of the demands on the players, and so it initially proved as both sides struggled to settle into a rhythm.
Chelsea was forced into an early change after Ashley Cole pulled up with a hamstring injury while chasing Danny Welbeck. He looked in severe pain as he hobbled off, to be replaced by Ryan Bertrand.
It took 30 minutes for the game’s first real opening, which came when Hazard played in Ba on the right. The striker shot powerfully to De Gea’s near post, but the United keeper was alert and smartly kept it out. Hazard looked the most likely player to conjure an opening. Running with the ball from the left, he skipped past Jones and shared a one-two with Oscar before smashing his shot narrowly over the bar.
Petr Cech nearly became the victim of a hopeful Javier Hernandez long-ranger. It did not wobble in the air as much as the goalkeeper’s reaction suggested, but the captain’s blushes were saved by his right leg.
Chelsea had ended the first period marginally in charge and took control early in the second through a superbly constructed goal that blew the cobwebs off what had been a tepid encounter.
Mata seemingly had few options when he picked up the ball in a central area in the middle of the United half. But the Spaniard’s feet are in perfect sync with his sharp football brain, and he picked out Ba’s run with a perfectly weighted chipped pass. The Senegalese had plenty to do, but had the technique to match his confidence. A brilliant first-time hooked finish on the volley surprised De Gea as much as onlookers to put Chelsea ahead for the first time in the two-legged tie.
United responded with typical vigor. Hernandez inspired one of the saves of the season from Cech with a diving header that had looked destined for the net. Robin van Persie and Ryan Giggs were then sent on in place of ineffective pair Tom Cleverley and Nani to save United’s FA Cup campaign.
Hazard gave United a let off after 67 minutes when he burst into the penalty area following a mistake from Carrick only to shoot a yard wide of the goal. It prompted a flurry of opportunities for the home side, but the team's finishing did not match its approach play as, time and again, chances sailed above and either side of the woodwork.
Mata ran the show late on but, despite late United pressure, the Chelsea survived without the security of a second goal.