Tom Lawrence and Connor Roberts were also on target the League B Group 4 clash, with Wales totally controlling its opening match of the Nations League.

Martin O'Neill's men were dreadful at Cardiff City Stadium and could have lost by more, Wales easing off after the break having established a 3-0 lead prior to the interval.

But the visitor scored a consolation through substitute Shaun Williams, who capitalised on a Ramsey error to chip Wales goalkeeper Wayne Hennessey.

The host was without a win in eight meetings with Ireland but it led inside six minutes.

Ethan Ampadu's crossfield pass created space on the Wales right, which Joe Allen exploited by sliding Lawrence through on goal, the Derby County man smashing in a near-post finish.

Another diagonal created Wales's superb second 12 minutes later, Ben Davies sweeping the ball out to Bale, who cut inside and curled a brilliant strike into the top-left corner.

Debutant Callum Robinson wasted a good chance for Ireland but Wales extended their lead again in the 37th minute, Ampadu robbing Jonathan Walters and striding forward to feed Ramsey, with his low drive again leaving Darren Randolph beaten at his near post.

Robinson headed a Seamus Coleman centre over the crossbar as Ireland sought a second-half response, but Wales were rampant and added their fourth in the 55th minute.

Lawrence teed up Bale on the left and Wales' star man fizzed the ball across the box, Roberts controlling with his right before lashing home an unstoppable 20-yard volley with his left.

Although Williams made the most of Ramsey's slip a comeback was never on the cards, leaving Giggs to mull over a superb team performance led by Bale and rising star Ampadu.