The €100million man scored for the first time in his past 17 internationals to give Wales a fifth-minute lead from the penalty spot, the first of two spot-kicks he fired home in Kazan.
Captain Bale then hit a stoppage-time winner past Sergey Chernik to give Wales a 3-2 success from their trip to Russia, with the game moved to the neutral location as Wales could not enter Belarus due to sanctions imposed against that country's government.
The tussle did not go entirely to plan for Wales, who conceded twice in quick succession around the half-hour mark, with just 92 seconds between Vitali Lisakovich's equaliser and Pavel Sedko putting the nominal home team ahead. Those had been the first two shots on target for Belarus.
But Bale levelled up in the 69th minute and then produced fresh heroics for his country in the dying moments. He had seven goal attempts in total, and the three he put on target paid handsome dividends for Wales' all-time record goalscorer.
He described the victory as "massive" and said: "We know these kinds of games are probably the hardest because you are expected to win and other teams make it difficult.
"To get that kind of last-minute goal and three points will hopefully keep our momentum going and hopefully we can keep that into the next game."
Wales had missed their previous three penalties, including Bale's failure at Euro 2020 against Turkey, and he admitted that big-stage blunder was in his thinking when he won the early spot-kick chance.
"Of course, you have it in the back of my mind," Bale told Sky Sports. "Missed penalties are a thing in football, it happens and it's about how you bounce back. It was great to score two tonight, because they were important goals.
"[The winner] was kind of last-gasp. Everything was in the box and bouncing around, and I tried to hook it in, and as soon as I saw it go just past his fingers and roll in, I was ecstatic. I knew it was right at the last few seconds."
Only once before had Bale gone longer without scoring for his country – a run of 20 games from 2007 to 2010, in the infancy of his Wales career.
Kazan is over 400 miles east of Moscow, and Bale was unimpressed by Wales being told to play there by UEFA.
"Obviously everything hasn't really gone for us in terms of travelling to Russia," said Bale. "It's not exactly ideal for UEFA or FIFA to put us here, but it is what it is and we've had to use that as extra motivation. Thankfully, we got the three points and we can get out of here."