Chris Coleman's side withstood a late rally from the visitors to clinch a well-earned win thanks to goals from the 23-year-old Tottenham winger and Burnley striker Sam Vokes
The hosts took the lead midway through the first half with a cool finish from Bale, before Vokes doubled the lead with a header early in the second. The Austrians did pull a goal back through Marc Janko late on but were unable to level matters despite dominating for large periods.
Chris Coleman named a strong starting line-up with Bale, Craig Bellamy and Joe Allen all involved despite upcoming Premier League and Championship games at the weekend.
Austria made the stronger start to proceedings and went close to opening the scoring inside the the opening minutes, first when Adam Matthews cleared a deflected corner off the line before Marko Arnautovic forced a good save from Boaz Myhill.
However, Wales responded to Austria's early dominance with a clear chance of their own, Bellamy shooting just wide after being put through by David Vaughan.
The visitors failed to heed that particular warning though and minutes later the Welsh were ahead as Bale latched on to a beautiful long ball from Allen to slot past Austria keeper Robert Almer from close range.
Coleman's men continued to make the running following the opener but Austria remained a threat with Emanuel Pogatetz heading wide from a free kick before seeing a goal ruled out seconds later for offside.
Austria surely sensed a vulnerability in the Welsh defence and they continued to push forward with freedom, Arnautovic forcing another strong save from Myhill, who was called into action shortly after to prevent a header from Sebastien Prodl from finding the net.
Marcel Koller's side were undettered by their faliure to find a leveller, and almost grabbed one in spectacular fashion as the impressive David Alaba hit the post with a superb left-footed volley from distance after the ball had fallen to him from a corner.
Coleman must have noticed his side fade towards the end of the opening period, and elected to change things at the interval bringing on Andy King and Vokes in place of Bellamy and Vaughan.
It was the latter of the two that had the desired impact, as Vokes powerfully headed in a Bale cross just seven minutes into the second half to double Wales' advantage.
Bale was involved in another Welsh attack just a few minutes after the second goal and should have extended the advantage further, firing a wicked left-footed strike just inches wide from 12 yards.
The Tottenham star was soon withdrawn following that chance and replaced by Hal Robson-Kanu, and with Austria making a string of changes as well, the game soon lost its natural flow.
That did not prevent Austria from trying to get something out of the game, however, and they finally gained a reward for their positive attacking play when the influential Arnautovic found Janko to nod past Myhill with just 15 minutes left to play.
Koller's charges continued to dictate play as the game ebbed towards its conclusion, but the Welsh defence stiffened to the challenge and were able to hold out to grab a confidence-boosting triumph.