The Welsh international came off the bench to clinch all three points as Spurs move up to second in the table.
Mourinho’s team were on top from the start in this one as Harry Kane and Sergio Reguilon forced early stops from Robert Sanchez.
And with Spurs coming in waves against the under pressure Seagulls defence, Kane edged them in front on 10 minutes.
The England skipper was fouled right on the edge of the box by Adam Lallana and after a long VAR check he confidently fired home from the spot.
Brighton looked to wrestle themselves back into it after the break as highly rated full back Tariq Lamptey netted his first ever Premier League goal.
Solly March stretched the Spurs defence in behind to pull back for Pascal Gross and he unselfishly fed in Lamptey to sidefoot past Hugo Lloris.
Mourinho threw on Bale in the closing stages to try and turn the tide and the Real Madrid loanee provided the vital impetus.
Toby Alderweireld’s pass sent Reguilon free in behind Lamptey and the Spaniard arrowed cross found Bale inside the box and the returning made no mistake to power past Sanchez.
Full Time at the Tottenham Hotspur Stadium it’s Tottenham 2 Brighton 1