It took a while for the home side to break through, but Bale opened the scoring with a fine finish on 36 minutes after Serge Aurier played him through on goal.
Bale put on a show in the minutes that followed, first converting after Son led a fast break and then completing his hat trick with a low shot via another Aurier assist.
Son added further gloss to the scoreline with a goal of his own to leave Ryan Mason's team on 56 points from 34 matches, five behind fourth-placed Chelsea.
Bale's display, albeit against the league's bottom club, will leave Tottenham fans asking why he was not given more opportunities to roll back the years by Mason's predecessor Jose Mourinho.
Eight of Bale's 14 Premier League appearances under Mourinho were as a substitute but he has started both of Mason's games in charge, albeit surprisingly only on the bench in last week's Carabao Cup final defeat by Manchester City.
It looks likely Bale will return from loan to Real Madrid at the end of the season, although after Sunday's display Spurs fans will be hoping he can extend his stay.
"You have to take your chances when they come so I'm feeling good," Bale said. "I just needed to play games and get a run of games and I'm doing that now.
"I'm happy and when I'm happy I play well."
Mason added: "Last week was disappointing for everyone. We had a week where we could train and work on the players. We defended strongly as a team. Some of our play was absolutely outstanding."
Information from Reuters was used in this story.