The champions are searching for a third successive victory, which would strengthen Chelsea's grip on fourth place, the most immediate target for Ancelotti's side after a difficult season.
The second half performance in the 2-1 win against United, though, served as a reminder of the Chelsea quality that remained hidden when they slipped away from the top of the Premier League during a disastrous run that placed a question mark against Ancelotti's future at the club.
David Luiz stood out in only his second start for the club while Fernando Torres showed signs of returning to the form that persuaded the Blues to pay out a British record £50 million for the former Liverpool forward.
And with passage into the quarter-finals of the Champions League virtually assured following the 2-0 first leg win against FC Copenhagen in Denmark, Ancelotti is understandably more upbeat.
"It was an important victory for us," Ancelotti said. "We put in a very good performance in Copenhagen and we maintained that.
"The team is living in a good moment and we want to maintain this preparing for the next game. It was an important performance.
"We were 1-0 down but we maintained our composure and, in the end, deserved to win. We won against a fantastic team that deserve to stay at the top of the table at this moment."
Midfielder Frank Lampard said after the United clash that the win would count for nothing unless Chelsea maintained their recent form at Bloomfield Road and Ancelotti agrees.
"It's an important game, a difficult game because Blackpool have had fantastic performances at home," he said.
"They beat Tottenham in their last home game, and were 2-0 up against United. It's one team who like to play football with intensity and a good pace, attacking football."
Torres's lack of goals will remain an issue until the striker finally gets off the mark but Ancelotti insists he is unconcerned.
He said: "Everyone here isn't afraid or worried because he hasn't scored. Everyone is looking at his performances.
"I'm asking him to have good movement for the team and to have combinations with the other strikers."
Chelsea cruised to a 6-0 victory over Blackpool in the first meeting in west London, prompting suggestions that the newly promoted club were certain to make a swift return to the Championship.
Blackpool recovered well after a difficult start but after registering just two wins in the last 12 games, they are in danger of getting dragged back into a relegation fight.
"It's scary what they did to us down there," said Seasiders manager Ian Holloway "They seemed to score every 10 minutes and it was a field day for them. We played them when they were absolutely flying.
"We could have played them a few months ago when we were doing better and they were having a troubled period.
"But we're going to find them at their best because they've just beaten Manchester United and we've got five or six players out."
Amongst the Blackpool absentees are midfielder Charlie Adam and striker DJ Campbell - both are suspended - and Holloway admits their absence could be crucial.
"We're not the same team without DJ or Charlie Adam," he added. "I'm going to have to look for some different strengths in the players I have got left to pick."