WALES’ World Cup qualifying group will go to the wire according to Republic of Ireland boss Martin O’Neill.

Sunday promises to be a vital round in the tussle for Group D top spot with Chris Coleman’s side, who are tied with Austria on seven points, heading to leaders Serbia, who are on 11 along with the Irish.

The group winner will qualify for the 2018 tournament in Russia with the second-placed team advancing to a play-off in order to qualify.

The Austrians travel to Dublin knowing that a repeat of their 1-0 November loss in Vienna would leave their qualification hopes hanging by a thread.

“It is a big week, but then every game is as important,” said O’Neill, whose side drew 0-0 with Wales at the Aviva Stadium in March.

“I keep going back to the time that we started out in the Euros - Aiden McGeady’s goals against Georgia proved every bit as important as the goal that Shane Long scored against Germany, so that’s the way it is.

“You have to try to accumulate points along the way. At the minute, we are doing fine, but the second half is the real business end of things and we have to really, really just be on our mettle, be very, very strong.”

Coleman’s side could do with a victory after drawing against Austria, Georgia, Serbia and the Irish since their opening round win against Moldova.

However, O’Neill believes defeat won’t be terminal for any side in a fierce group.

He said: “You never know in football. A defeat doesn’t rule anyone out, especially in our group, where a lot of teams are going to take a lot of points off everyone. I wouldn’t rule out anyone yet.

“It’s the same for us. If it’s a defeat, it’s not the end of the world, but it’s a huge game and Austria are going to take points off a lot of teams.

“Our aim is to just focus on us, and we’ll see on Sunday. But we’re confident going into the game that we can take another step towards where we want to be.”

Real Madrid forward Gareth Bale and Aston Villa defender Neil Taylor are suspended for Wales’ game in Belgrade.