Having collected only four points from their opening four games, Belgium needed a big performance against a team which started the night second in Group A. And they got what they were looking for as Axel Witsel scored early in each half and they restricted the hosts to a series of half-chances.
Belgium wasted little time in taking the lead, with Witsel nodding home in the sixth minute. Marvin Ogunjimi appeared to be in an offside position when the ball was lofted into the area, but with the Austrian defence stood in a line, Witsel raced through to beat Jurgen Macho for an easy finish.
Janko had a chance to respond for Austria after Daniel van Buyten's attempted clearance took a fortunate deflection for the hosts, but the striker took a heavy touch as he closed on goal, allowing Sunderland goalkeeper Simon Mignolet to nudge the ball away for a corner. Ekrem Dag then had an ambitious effort from 30 yards, but it was always a little too high.
Belgium still looked by far the more dangerous side and Moussa Dembele went close just after the half-hour mark. The Fulham man got good power on his low shot as he tried to sneak it through a busy defence, but it was too straight to beat Macho. Moments later Dembele had another chance as he easily beat the badly overcommitted Christian Fuchs, but he fired wide from a good position.
Julian Baumgartlinger almost got a fortunate equaliser before half-time when his shot ballooned up off Vincent Kompany to wrong-foot Mignolet, but it landed on the roof of the net.
Belgium started the second half strongly and Nacer Chadli had already shot narrowly wide when Witsel got his second. The defence was badly at fault as Laurent Ciman's cross found Witsel goalside of Martin Harnik at the far post, and a good touch with the chest afforded him time and space to blast home from close range.
With the second goal in the bag, it was a largely subdued second half until a late chance for Harnik to make amends, but Mignolet was again out quickly to make the block. The win moves Belgium level with the hosts on seven points, although Austria still have a game in hand.