Two goals from Harry Kane, after Heung-min Son’s opener, had Spurs cruising after just 16 minutes.
The game’s pace slowed from there and West Ham kept improving after the break. Bale was introduced for his second debut before the Hammers comeback began.
Fabien Balbuena headed home with eight minutes remaining, before Davinson Sanchez put past Hugo Lloris and, in the 94th minute, Manuel Lanzini found the top corner from distance.
Following the game, a NBC Sports reporter started asking Mourinho about Bale only for the Spurs manager to interrupt.
He said: “Before the match you wanted to talk about Gareth Bale, after the game you want to talk about Gareth Bale. It’s Tottenham vs West Ham.”
The interviewer swiftly ended the interview, throwing back to the studio where the presenter said: “If you’re going to play Gareth Bale, people will ask about Gareth Bale.”
When asked by Sky Sports to explain the final result, Mourinho said: “Football … football happened.”
He added: “To concede three goals is a big punishment, and deserved.”