Tottenham suffered a shock 2-0 loss to Sporting Lisbon at the Estadio Jose Alvalade Stadium in a Champions League Group D encounter on Tuesday.
Two injury-time goals from Dias Fernandes and Gomes Lourenco handed the hosts the maximum points.
Tottenham were guilty of missing numerous chances, and they would rue their inability to score and lack of concentration in the closing moments of the game.
Sporting Lisbon had goalkeeper Adan to thank for his stunning performance, making numerous saves to deny Tottenham the chance to score.
It was a night of substitutes as Paulinho and Arthur Gomes came off the bench to hand Sporting Lisbon a shock win.
Paulinho headed in Pedro Goncalves' corner to give the hosts the lead before another substitute, Arthur Gomes, completed the job with a low effort.
Tottenham have now lost their first game of the season, and they have also failed to score for the first time this season.
Sporting Lisbon won their first match in the Champions League beating Eintracht Frankfurt 3-0 in Germany, while Tottenham earned a 2-0 win over Marseille in London.
Sporting Lisbon will be back in Champions League action with a trip to France to face Marseille, while Eintracht Frankfurt welcomes Tottenham to Germany.