The Saudis missed a second-half penalty and had a first-half goal disallowed. The ball bounced down from the crossbar and appeared to cross the line but the referee waved play on. The result put the Irish level in second place with Australia on three points. Mexico, who beat the Australians 3-1, lead the group and became the first side to reach the second round.
The holders, Argentina, slumped to a 1-0 defeat against Ghana, for whom Peter Ofari-Quaye scored a late winner.
The host nation, Nigeria, overcame Germany 2-0 for their first victory. Second-half goals by Ganiyu Shittu and Hashimu Garba defeated the Germans, who were without Enrico Kern, their hat-trick hero against Paraguay on Sunday. Paraguay beat Costa Rica 3-1 yesterday.