South Wales Police says missing Ben Thompson from Haverfordwest had been enjoying the rugby international in Cardiff on Saturday.
The 34-year-old was last seen in Cardiff city centre on Saturday.
He is described as 5' 9" tall, with short brown hair and blue eyes, and he was last seen wearing brown boots, blue jeans, and possibly a blue & a white striped top with a green jacket.
Anyone with information is asked to call their local police on 101.
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