Everton manager Roberto Martinez said his side's 3-0 defeat to Southampton represented "a real setback."
Everton had enjoyed a comfortable 3-1 victory over Queens Park Rangers on Monday but were well beaten at St Mary's, with Graziano Pelle and Maya Yoshida on target following a first-half own goal from Romelu Lukaku.
"It is a setback," Martinez said. "Obviously, we had a very good result on Monday. As you can imagine, we wanted to follow that through.
"I don't think we've been involved in a good run of results like we did last season and that is what we are chasing.
"Clearly, it is a real setback. I thought Southampton had been in a very unfortunate run and I don't think they deserved to lose all the games that they did, but today they had all things going their way.
"That is football. From our point of view, we just need to get ready for the game against Stoke at home and make sure we get a good run of results now."
Martinez said Everton's defending had let them down on the day.
"The most disappointing thing was the way we defended our box," the Spaniard said on the club's official website. "We were a little bit soft and were undone by three balls that went into the six-yard box.
"We are to blame for the defeat because we didn't defend any simple ball into the box well. Our record shows that we are normally a lot better in that respect and that is where we lost the game.
"The second half we started with a good mentality and we had Southampton where we wanted them. All they wanted to do was work on the counter-attack.
"But it was disappointing to concede three goals the way we did. Clearly it was a day when nothing went in our favour because even when we created opportunities we never hit the back of the net. The difference between the two sides was in the boxes."
Martinez did not make any changes during the game and he explained: "I did feel that the team was the right one to get back into the game. I wanted the players to show the right intention to get back into the game.
"I never felt that we were outplayed -- it was a matter of the way we defended our 18-yard box rather than any tactical aspect."