After a goalless first half, West Ham scored three times after the break as Spurs lost their unbeaten home record.
"We have conceded three goals today but before we were the team who conceded the least chances," BBC Sport quotes the Portuguese coach as saying. "This time West Ham managed to surprise us and we have to bounce back. This would be a good goal for us.
"It is [a wake-up call]. 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."
Spurs are now sixth in the table and can get back to winning ways against Aston Villa after the two-week international break.