Spurs have now lost 5 out of their last 6 Premier League matches and are now 9 points away from the top 4.
After Tottenham's defeat Spurs boss Jose Mourinho said: “The result is there, they have the points and we have the sadness and the frustration.
“The good feeling is the way the team played, especially in the second half. No doubts the team wanted to win, no doubts the team was fighting together for a different result, and I believe we deserved a different result.
“West Ham didn’t play in the second half, they just fought and defended. We played, we created chances, we scored a goal, should score more, hit the post twice, had fantastic crosses across the face of goal waiting for a touch, even sometimes an own goal. We had great positions from the edge of the box, shots that normally you think that Sonny, Harry or Lucas are going to score, so, also not lucky. But we cannot forget that the score was 1-0 and somehow after a couple of minutes in the second half it was 2-0.”
Tottenham's next Premier League game is at home to Burnley, next Sunday (28 February).