Fromer Leeds United striker Robbie Keane marked his final appearance for the Republic of Ireland with his 68th international goal to equal German great Gerd Muller’s career tally.
The 36-year-old, making his 146th appearance for his country, scored with a 30th-minute volley to ensure his big night at the Aviva Stadium went with a bang.
Robbie Brady had earlier fired the home side into an eighth-minute lead with his third goal in as many games for Ireland, and Jonathan Walters added a third 11 minutes before the break.
The visitors were starting to come into the game with the Republic careless in possession, but the moment for which the crowd had been waiting almost arrived with 26 minutes gone.
Keane picked up possession inside the penalty area and cut inside past defender Nadir Mabrook, only to lose out to the covering Abdu al Mukhaini.
Two minutes later, he was in on goal again and lifted his shot over the keeper, but agonisingly over the crossbar too.
But Keane was not to be denied and his when Walters helped on Brady’s pass with a clever flick, he teed himself up with his first touch before thumping a volley past Al Rushaidi to equal Gerd Muller’s international career tally of 68 goals.
It was 3-0 within four minutes with Brady once again involved, this time crossing for Walters to plant a firm header inside the far post.
But Oman continued to battle gamely and Westwood was called upon once again eight minutes before the break to save a long-range Al Saadi shot which bounced nastily in just front of him.
Keane scored 10 goals for the Whites in 33 appearances including a League Cup hat-trick against Leicester City.
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