Mauricio Pochettino insists Tottenham are still fighting for the Premier League title despite their defeat on Friday Night Football.
Chelsea will be champions if they win their next two matches - against Middlesbrough on Monday Night Football and at West Brom next Friday, both games live on Sky Sports.
Manuel Lanzini's second-half strike settled the match at the London Stadium, leaving Spurs with a mountain to climb in the title race.
Live Monday Night Football
But Pochettino says his side will not give up their pursuit until it is mathematically impossible.
"We are still fighting. It is disappointing with the result, now we wait for the Chelsea result then it's three games ahead to play," he told Sky Sports.
"You all know now it is more difficult to catch Chelsea but we need to try always until the end."
Harry Kane and Heung-Min Son went close for Tottenham before Lanzini's winner and Pochettino felt his side did not take their opportunities when on top.
"First half we dominated and created many chances to score," he added. "A few clear chances. Second half we started a little bit sloppy and we conceded a little bit more space.
"When you are fighting for the title, the goal we conceded, you need to stop before and not concede this type of goal.
Live Nissan Super Sunday
"Then it is so difficult. They played deeper with a 5-4-1 formation. It was difficult to find the space. We were a little bit unlucky, I don't think we deserved to lose. But we lost and now we look forward."
Pochettino conceded his side failed to match the intensity they showed in their 2-0 north London derby victory last weekend, adding: "I think that it is true that it was a difficult game. If you compare to five days ago against Arsenal, it was a completely different game.
"It wasn't the same performance we played last week. I think all the players are disappointed about that. There's nothing to say."
When asked if Spurs failed to cope with the pressure, Pochettino said: "In football a lot of topics make me laugh because we arrived at West Ham after [winning] nine games in a row.
"I have listened to that in many weeks. When you lose, OK maybe it's because of the pressure. Maybe because the bad performance. Maybe because many topics you can add and justify why we lost.
"The reality is we didn't score."