Tom Huddlestone struck the post with a free kick inside the opening five minutes as Spurs made a bright start to the match.
However, Tottenham's lead was short-lived, with Emmerson Boyce rising high to head a corner past Hugo Lloris just two minutes after Bale's goal.
Bale and Jermain Defoe both had chances to restore the London side's lead before the half-time interval, but the hosts were able to prevent their opponents from adding to the score board.
Despite Spurs' strong finish to the first half, it was Wigan who had the better start to the second period, with Callum McManaman driving the ball into the net within five minutes of the restart.
The visitors dominated possession throughout the second half but created few goalscoring opportunities until the final minute of normal time, when Boyce turned the ball into his own goal from a Spurs free kick.