Roberto Martinez said he had feared Everton would lose to Aston Villa on Saturday after their 3-0 victory over Manchester United the previous weekend.
Everton lost 3-2 at Villa Park, finding themselves 2-0 down at the break to a Christian Benteke brace and looking distinctly second best.
Romelu Lukaku reduced the arrears after the break before Tom Cleverley made it 3-1 and, despite Phil Jagielka's late goal, Villa came away deserved winners.
He said: "I was worried about exactly what happened: coming here and not having the engagement or stimulation after having such a fantastic performance and result and atmosphere at Goodison.
"It happens in football -- the intensity and tempo we had in our last game maybe made it a bit difficult to start the game in the same level. I did feel in the first half we were second best in everything we did.
"It's fair to say Villa were the better side in the first half and we were the better side in the second.
"We couldn't get through that poor period without damage. I thought the damage of giving a two-goal lead was huge.
"The reaction was very good, there are dressing rooms which maybe cannot react or find that intensity but we did that and performed in a completely different manner."
Information from the Press Association was used in this report.