Leicester City came from behind to stun Tottenham on Saturday at the King Power Stadium.
Ricardo Pereira had put the Foxes back on level terms, moments after Spurs had been denied a second goal when Serge Aurier's low drive was disallowed for a marginal offside call against Son Heung-min.
Harry Kane's fourth league goal of the season had given Spurs the lead in the first half, the England striker slotting Son's clever flick beyond Kasper Schmeichel despite being knocked off balance by Foxes defender Caglar Soyuncu.
Tottenham manager Mauricio Pochettino said afterwards: "That is football. It is true to concede two goals every game makes it difficult to win. Before we concede we were the best side. I am disappointed with the result but we have to keep working hard.
"Both sides are affected by this situation (VAR decision to rule out Aurier goal). If we score the second the game is over. It gives belief to a team that could have been dead. After we concede at 1-1 we had chances to score the second. But in Premier League it is the most beautiful league because it is never over. In the big picture, I am disappointed but very positive and optimistic.
"We need to improve our performance away from home. We are going to work hard and improve."