James McClean was the Republic of Ireland hero once again as Martin O'Neill's men took another step towards the World Cup finals with a 1-0 victory in Austria.
West Brom winger McClean netted twice as Ireland won 3-1 in Moldova last month and grabbed the winner shortly after half-time in Vienna with a wonderful goal totally out of place in a largely forgettable game.
The win enabled Ireland to take control of Group D with 10 points from four games, three ahead of Serbia, who meet Euro 2016 semi-finalists Wales later on Saturday.
Austria's hopes of a play-off spot look remote already and it was not hard to see why after a performance that started in encouraging fashion but tailed off badly.
Having won just one of their opening three pool games the onus was on Marcel Koller's side to seize the initiative early on and they duly obliged, Marcel Sabitzer shooting wide after six minutes and Marc Janko seeing a snapshot smartly saved by Ireland goalkeeper Darren Randolph.
The visitors finally settled, although their progress was repeatedly hampered by an inability to maintain possession in midfield where Harry Arter was making his competitive debut.
McClean flashed a shot wide after 13 minutes, but their best chance came shortly before the break, Wes Hoolahan and Robbie Brady combining nicely down the left before the latter whipped in a cross that a lunging Jonathan Walters was unable to convert, his shot clipping the crossbar on its way over.
In between, it was Austria who offered the greater threat in the opening 45 minutes.
Only a wonderful challenge from Ireland captain Seamus Coleman prevented the lively Marko Arnautovic from shooting on goal when in a promising position while Sabitzer was unlucky to see his clever chip come back off the bar following a neat ball from the Stoke City forward.
Ireland came roaring out of the blocks at the start of the second period and took the lead with an outstanding counter-attacking move.
David Meyler, a 24th-minute substitute for the injured Glenn Whelan, started it near to his own corner flag before picking out Hoolahan just inside his own half. The Norwich City midfielder took his time before slipping in McClean and, despite a poor first touch, he drilled a low drive through the legs of Austria goalkeeper Ramazan Ozcan.
It was nearly 2-0 three minutes later, Brady's inswinging free-kick from the right headed in by Walters although the referee's assistant rightly ruled it out for offside.
Ciaran Clark saw a header cleared off the line by Sabitzer as Ireland continued to dominate with Austria reduced to long-range shots to try to get back in the contest.
Louis Schaub stung the palms of Randolph, the uncharacteristically awful David Alaba flashed a 30-yard effort just over before Aleksandar Dragovic's late drive was deflected kindly into the hands of the Ireland goalkeeper.
Austria's final chance, deep into stoppage time, fell the way of Janko, but he was unable to divert Julian Baumgartlinger's volley on target as Ireland held on.