Wales started on the front foot, and industrious Liverpool youngster Lewis Koumas popped up in a great position early on, but the offside flag went up anyway as he fired his effort just wide.
Portugal soon adjusted to the aggressive pressing from Bellamy’s side, and Cristiano Ronaldo had the first sight of goal for the hosts, flashing his effort past the far post from a tight angle.
Ruben Dias then went close from a well-worked corner, meeting Bruno Fernandes’ cross and guiding it narrowly over the crossbar.
Portugal began to dial up the pressure, and a teasing delivery from Nuno Mendes threatened to prise open the defence, but Pedro Neto just couldn’t stretch enough to make the right connection at the back post.
Moments later, the Selecao das Quinas had the lead, as Joao Felix managed to beat Danny Ward from just outside the box with the aid of a slight deflection.
Much of the ground thought that Ronaldo had doubled the advantage, but his left-foot volley flew wide, bouncing back off the advertising hoardings to ripple the net deceptively.
Ronaldo had a golden opportunity to double the advantage at the start of the second half, although the ball once again fell to his weaker side, and he couldn’t control his first-time finish with the goal at his mercy.
That almost proved costly when Wales broke the other way, with Brennan Johnson going down in the box, but a VAR check upheld the decision not to award a penalty. David Brooks then looked to have spurned a huge chance to equalise, only for the flag to render the miss irrelevant, just as it did for Koumas earlier on.
However, the biggest offside decision of the lot belatedly went Wales’ way, as Ronaldo saw his strike chalked off by VAR after making his run marginally too soon.
That kept the Dragons firmly in the contest, and Johnson must have thought he’d squared up the contest, but his inventive chipped effort bounced off the crossbar before Dias scraped the rebound off the line.
The visitors finished on top, with substitute Kieffer Moore looking dangerous, but they ultimately lacked the cutting edge to find the all-important goal.
The result means Portugal are off to a winning start in their quest to retain the Nations League, having won half of the four editions held to date. It’s also a successful start to the Jorge Jesus era, with the new boss extending a long home unbeaten run to 11 games (W10, D1).
Bellamy has at least improved upon the 3-0 defeat he suffered as a player in this fixture in 2000, but that won’t save him from intense scrutiny.
Flashscore Man of the Match: Joao Felix (Portugal)