Austria 0 Republic of Ireland 1
The Republic of Ireland have beaten Austria 1-0 in their World Cup qualifying Group D match in Vienna.
The win puts the Republic top of their World Cup qualifying group - if only for a few hours.
James McClean scored the goal that beat Austria 1-0 after 48 minutes.
Robbie Brady picked up a yellow card and will miss the next qualifier against Wales.
Ireland could be knocked off the summit if Serbia win in Wales this evening which kicks off at 7.45pm.
Harry Arter was handed a competitive debut for the Republic of Ireland as manager Martin O'Neill charged him with the task of replacing James McCarthy for the World Cup qualifier in Austria.
The Bournemouth midfielder was included in one of three changes to the side which won 3-1 in Moldova last time out, with Robbie Brady and Jeff Hendrick also coming in for Stephen Ward and Shane Long, while James McClean shook off a back problem to retain his place.
Austria boss Marcel Koller kept faith with the bulk of the team which lost 3-2 to Group D leaders Serbia in Belgrade last month as midfielder Alessandro Schopf replaced the injured Zlatko Junuzovic.
Austria flew out of the blocks and Ireland found themselves having to defend for dear life in the early stages.
Brady, lining up at left-back in the absence of Ward, had to turn a first-minute Marko Arnautovic left-wing cross out for a corner after it had been allowed to travel alarmingly across the six-yard area, and Hendrick headed behind seconds later after Schopf had set up Marcel Sabitzer to deliver from the right.
Darren Randolph's goal came under threat once again with five minutes gone when Arnautovic cut inside and saw his effort blocked by Ciaran Clark before Sabitzer dragged the rebound wide.
It got little easier for the visitors and Randolph was grateful to grasp Marc Janko's eighth-minute shot on the turn after David Alaba had picked him out with a near-post corner.
However, the Republic went close to taking the lead from their first attempt five minutes later when McClean turned smartly and saw his right-foot shot deflected just over the angle of bar and post.
But the home side responded and Janko might have done better when his weak header was claimed by Randolph after Sabitzer and Arnautovic had exchanged passes down the left before the former picked out the striker in front of goal.
Defender Shane Duffy went to ground as he attempted to meet Arter's 22nd-minute corner, but Russian referee Sergei Karasev was unimpressed, and Ireland's fortunes took a further turn for the worse in the aftermath when midfielder Glenn Whelan pulled up and had to be replaced by David Meyler.
The visitors survived a fresh scare as the game reached the 25-minute mark when Duffy's poor clearing header fell nicely for Janko, but although the frontman's chest control was good, his shot was not.
With skipper Julian Baumgartlinger and Alaba sitting in front of the back four and orchestrating from deep, O'Neill's men were struggling to win enough possession to mount any sustained pressure, although for all they were seeing much more of the ball, Austria were not troubling Randolph.
Ireland went close 14 minutes before the break when Jonathan Walters got his head to Robbie Brady's free-kick, but glanced his effort just wide.
Skipper Seamus Coleman had to make a fine block at the other end two minutes later to deny Arnautovic, whose claims for a penalty were instantly dismissed.
The visitors enjoyed a stroke of good fortune with six minutes of the half remaining when Sabitzer was played into space on the right side of the penalty area and chipped the advancing Randolph, only to see his effort come back of the bar for first Clark and then Hendrick to clear.
Walters was denied in similar fashion on the stroke of half-time when his lunge to meet Brady's teasing cross saw him divert the ball on to the top of the bar.
O'Neill's men resumed in more positive fashion than that in which they had started the game and they took the lead with less than three minutes of the second half gone.
Austria had been on the attack, but squandered possession deep inside the Irish half, allowing the visitors to hit them on the counter.
The ball was fed to playmaker Wes Hoolahan, whose pass was perfectly weighted for McClean to sprint clear down the left and drive a low shot past helpless keeper Ramazan Ozcan and inside the far post for his third goal in two games.
They thought they had extended their lead when Walters headed Brady's 51st-minute free-kick home, but he did so from an offside position and the effort was correctly ruled out.
But it took a fine diving save by Randolph to preserve his side's lead when substitute Louis Schaub took aim from distance.
The keeper might have been in action again just past the hour mark when Austria were awarded a free-kick in Alaba territory, but the Bayern Munich star's effort was wayward to say the least.
Alaba went significantly closer with 65 minutes gone when he sent a dipping left-foot shot onto the roof of the back-pedalling Randolph's net, a further warning that the game was far from over.
Having conceded late Alaba goals in each of their past two matches against the same opposition, there was relief when Randolph safely fielded defender Aleksandar Dragovic's deflected 90th-minute strike.
Janko should have levelled deep into injury-time, but headed criminally wide from Baumgartlinger's drive across the box as Ireland survived.
Georgia 1 Moldova 1
A stunning equaliser from Alexandru Gatcan earned Moldova a 1-1 draw away to Georgia in Tbilisi.
Georgia took the lead on 16 minutes when midfielder Valeri Qazaishvili cut back inside at the edge of the penalty area before curling his shot low into the far corner.
Moldova, though, grew into the match during the second half and secured a first point of the Group D qualifying campaign with 12 minutes left.
Rostov midfielder Gatcan collected the ball on his chest at the edge of the Georgia penalty area, before firing a dipping volley up over goalkeeper Giorgi Loria into the far corner.