Andre Villas-Boas believes that Tottenham's surprise 3-0 home Premier League defeat to West Ham is a "wake-up call" for his squad.
After a goalless first half at White Hart Lane, Sam Allardyce's side scored three times in 13 second-half minutes to secure West Ham's first Premier League win away to Tottenham since 1999.
Winston Reid opened the scoring when he tapped home after team-mate Kevin Nolan had inadvertently blocked his header.
Ricardo Vaz Te then doubled the advantage after springing the offside trap before a fine solo effort from Ravel Morrison earned West Ham their maiden away success of the campaign.
Tottenham manager Villas-Boas admitted that West Ham were more clinical with their opportunities, and the Portuguese called on his side to bounce back from the loss quickly.
"It is (a wake-up call)," he said. "This fixture was a bit dangerous.
"If we won everything (it) would be spectacular but if you draw or lose you drop into a position you don't want to be. Either way, we have done well so far.
"I think they scored in a moment when they were very, very strong - through set plays, they got first to the second ball.
"It can happen in games like this. We didn't have that quick reaction to get back into the game because they scored the second soon after.
"The game started (at) 100 miles per hour for both teams, with both looking threatening. They had good spells and so did we.
"The second half we were not first to the ball in the 50-50 duels. They were a bit more aggressive and punished us.
"We have conceded three goals today but before we were the team who conceded the least chances. This time West Ham managed to surprise us and we have to bounce back."