The Welsh ace scored his fourth goal in three European appearances against the Nerazzurri following his hat-trick at the San Siro in the Champions League group stage in 2010 to help Andre Villas-Boas' side tally a healthy lead for the return trip to Milan next week.
Bale, who will miss that match after picking up a yellow card for diving (his third of the competition), gave Spurs the lead in the sixth minute of the Europa League Round of 16 first leg when he neatly headed home Gylfi Sigurdsson's cross from the left.
Eight minutes into the second half, Tottenham found themselves three to the good when defender Jan Vertonghen headed home a Bale corner and that was enough for the North Londoners to go through to the second leg full of confidence.
Tottenham have now won six of their last seven in all competitions with Bale scoring ten goals in his last eight outings ahead of their Premier League trip to Liverpool on Sunday.
For Andrea Stramaccioni's Inter, they look to Bologna in the Serie A this weekend but for the second leg with Spurs have the comfort of knowing they have performed well at home since the end of September, winning 11 and drawing five.
2012/13 UEFA Europa League - Round of 16 first leg
White Hart Lane, London - 34,353