Republic of Ireland lead Oman 1-0 at half time at the Aviva Stadium in Dublin, thanks to Kevin Doyle's strike.
New Crystal Palace striker Doyle struck on 19 minutes when he attacked the near post to guide Robbie Brady's corner into the net.
Shortly before the goal, the home side began to pile the pressure on, and Stephen Quinn fired in an effort after Brady's initial effort was blocked by the Oman defence.
Eid Al Farsi should have levelled for the visitors, but the striker could only strike the ball straight at Shay Given after escaping the attentions of the Irish defence on the half-hour mark.
Minutes later Alex Pearce had a header cleared off the line, before David Meyler's effort bounced off the crossbar.
