The Paraguayan defender played a good game, after being left without action in the previous match in the defeat against Wolverhampton.
This Monday, just like the opponent, Tottenham needed this victory to stay close to the positions that grant access to Europe, especially after not achieving a win last week against Manchester United.
With a much better game than the one displayed against the 'Red Devils', albeit against a weaker opponent, Tottenham enjoyed possession of the ball and the best chances, thanks to a brilliant Giovani Lo Celso in midfield.
The Argentine produced the most dangerous play of the first half, when he left Son in a difficult position in the area and the Korean turned to find the net with a powerful shot. However, the goal was overturned by VAR, which detected an offside in Lo Celso's filtered pass.
Although technology denied the goal to Mourinho's team, who was sulking in his seat, Tottenham did not stop trying in the second half. The clearest chance fell to Harry Kane on a counterattack.
The English forward took a first-time left-footed shot that went just wide of West Ham's goal.
But Tottenham still had one lucky break left. In a corner kick, Moussa Sissoko headed the ball down, seemingly without danger, but Tomas Soucek accidentally pushed it into his own net. This time, there was no VAR to save West Ham.
David Moyes' team timidly sought the equalizer and had a shot hitting the post by Jarrod Bowen, but just a few minutes after the woodwork, Tottenham took advantage of a counterattack to leave Kane alone against the goalkeeper and for the English forward to score his first goal since December 29.
Tottenham is now seventh in the table with 45 points, six points away from the positions for the Champions League, while West Ham continues flirting with relegation and is seventeenth, level on points with Bournemouth.