Sir Alex Ferguson admitted he altered his Manchester United team selection for the Everton game after Manchester City's shock defeat by Southampton.
City were beaten 3-1 at St Mary's on Saturday, which meant United's 2-0 win over Everton put them 12 points clear at the top of the Premier League.
Ferguson said he planned to make "seven changes" but named a stronger side.
"When I saw the result yesterday, I knew how important the game (against Everton) would be for us," he said.
Rio Ferdinand and Michael Carrick were the only key omissions from the starting line-up as goals from Ryan Giggs and Robin van Persie sealed the win over David Moyes's men.
Ferguson was full of praise for 39-year-old former Wales captain Giggs, whose goal ensured he maintained his own record of scoring in 23 consecutive seasons.
"His legacy lives on, he is a fantastic human being," Ferguson said. "He's up and down that pitch all day and has shown fantastic energy for the game, it is wonderful to see."
Manchester United travel to Real Madrid for their Champions League last-16 tie on Wednesday, a match which they go into in strong form with 13 of their past 17 games ending in victories.
Real manager Jose Mourinho was at Old Trafford for the Everton game, and Ferguson is looking forward to again pitting his wits against the Portuguese.
"I had a chat with him, they had a great result yesterday," Ferguson said. "It will be a fantastic match on Wednesday."