In his pre-match interview, Bellamy said his team would "suffer" at times in the Portuguese capital.
His prediction was emphatically correct as Wales - following their promotion from League B in the head coach's first campaign in 2024 - found the jump up a step too far.
Despite Wales' encouraging start and positive moments in possession, the home side constantly threatened and looked comfortable in keeping the visitors at bay.
The intent against such a stellar opponent was admirable, although - unfortunately from a Wales perspective - the gulf in class between the sides was evident for long periods.
That was until Wales started to take more risks and played with increased confidence. Bellamy's substitutions helped to galvanise the team too.
In the blink of an eye, Portugal looked concerned, and the mood among the home fans started to shift.
Kieffer Moore's overcooked cross to Dan James, Johnson's delicate effort on to the top of the crossbar, Koumas' close-range shot, Wales had their moments.
It was not to be, although given the concern around the squad amid injuries to key players including Harry Wilson, Karl Darlow, Joe Rodon, Dylan Lawlor and Nathan Broadhead ahead of the match, the Red Wall will be far more pleased than they were before the game given the immense efforts of their players in Lisbon.