Spurs were in front in the 63rd minute when Bergwijn brought down a pass from Lucas Moura with his chest, controlled the ball on the turn and volleyed into the bottom corner. The winger only arrived four days ago from PSV Eindhoven.
Shortly after Bergwijn came off with cramp, it was Tottenham’s record-signing from the summer transfer who helped to create the second goal.
Tanguy Ndombele had been on the pitch barely a minute when he sent the ball through to Son, who struck past goalkeeper Ederson in the 71st minute.
Mourinho was ecstatic after being infuriated in the first half and laughing in bemusement as decisions went against Tottenham.
Raheem Sterling avoided being sent off for fouling Dele Alli. In a separate incident play was rolled back several minutes for VAR to award a penalty for a tackle by Serge Aurier on Sergio Aguero.
Tottenham goalkeeper Hugo Lloris saved the spot kick from Ilkay Gundogan.
But then VAR assessed whether another penalty should be awarded for Lloris’ block as Sterling tried to latch into the loose ball.
As that VAR review was being conducted, both sets of players clashed and no penalty was awarded but referee Mike Dean dished out several yellow cards.
Earlier, Arsenal were held to a goalless draw at Burnley, but Mikel Arteta’s side will count themselves lucky to have left with a point.
Jay Rodriguez and Jeff Hendrick missed golden chances for Burney to win a match they dominated for large stretches.
Arsenal started brightly and the returning Pierre-Emerick Aubameyang should have put them in front when he got round the back of Burnley to collect a through ball from David Luiz but sent his shot wide.
The Clarets looked the more determined, however, and with Dwight McNeil causing trouble down the left flank, they caused Arsenal plenty of problems after the break.
Hendrick headed wide a McNeil cross from a great position and Rodriguez blasted against the underside of the bar from close range after more good work from the Burnley winger.
The result left both sides on 31 points, with Arsenal in 10th place and ahead of Burnley on goal difference. The Gunners have won just one of their seven league matches since Arteta took charge following the dismissal of Unai Emery.
AP with Reuters