The Spurs boss acknowledges that the Hammers were "more aggressive" at times after the visitors shellshocked White Hart Lane with three goals in the second half
Sam Allardyce's side scored three times in 13 second-half minutes to secure the Hammers' first league win at White Hart Lane since 1999.
The Portuguese remarked that West Ham were more clinical with their opportunities and called on his side to bounce back from the loss quickly.
Asked by reporters if the result was a wake-up call, Villas-Boas replied: "It is. 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.
"[In] 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 but before [this game] we were the team who conceded the least chances. This time West Ham managed to surprise us and we have to bounce back."