Valon Behrami does not believe West Ham can afford to keep conceding early goals.
The Hammers fell behind against Portsmouth on Boxing Day but stormed back to secure an emphatic 4-1 victory.
West Ham then beat Stoke 2-1 on Sunday, but only after the Potters had opened the scoring through Abdoulaye Faye.
Behrami impressed in both games and was delighted to help West Ham claim the maximum three points.
However, he feels West Ham must make sure they are alert from the first whistle in future.
Behrami said: "I'm happy with the result. We have to carry on doing this and collecting points to push us up the table.
"The character is good but we can't fall behind every time. We can't just switch on when we go behind. We need to switch on from the start because it's not always easy to come back.
"But it's always nice to win these kinds of games."