Leyton Orient manager Russell Slade praised his side's attitude from the first whistle after the 3-1 win against Bournemouth.
A brace from Charlie MacDonald and a goal from Kevin Lisbie were enough to see off the promotion hopefuls, who replied through Brett Pitman.
"The most important thing was that we had a real focus in our performance from the first minute until the last," said Slade.
"It was a really good performance, not only were we good between the two boxes but I also thought we were good in the box against what was a very good side.
"They never stopped coming at us, they kept trying to create chances and cause us problems but I thought that we dealt with them very well."
The Cherries are experiencing a worrying loss of form having slumped to their fourth straight defeat.
Boss Eddie Howe said: "The goals that we conceded were really poor.
"At any level that you play, you can't gift teams goals and I felt we did, particularly with the first two goals.
"Leyton Orient didn't have to work hard for them, we gift-wrapped them and unfortunately, that's something that has crept into our game in the past few weeks. It's something we need to address immediately."
The Cherries were without injured central defender Tommy Elphick, and Howe added: "I don't want to talk about players who weren't playing but Tommy is our leader of the team and he's been a voice as well. Take his voice out of the group and it's made a difference to be honest. I've felt we've missed his influence, his demeanour, his leadership and his voice. But he's not here and we've got to get on with it."