Portugal head coach Fernando Santos likened Cristiano Ronaldo to a "port wine" after the 33-year-old fired the European champions closer to the World Cup knockout stages.
Ronaldo headed in the winner after four minutes to sink Morocco 1-0 at Moscow's Luzhniki Stadium – his fourth goal in two matches. It meant Portugal moved on to four points from their two Group B games while Morocco can no longer qualify after failing to improve on their opening-match defeat to Iran.
The Real Madrid superstar may no longer be the mesmerising winger he was in his early days at the Bernabeu, and at Sporting CP and Manchester United before that, but he has adapted his game to become arguably the finest number nine in world football.
Asked for the reasons behind Ronaldo's explosive start in Russia, Santos said: "He has a great coach!
"Cristiano, he's like a port wine, he knows how to age well.
"His physical prowess, his strategy… he is constantly evolving because he knows himself what he can do.
"He doesn't want to do today what he did four years ago. In four years' time he won't be doing what he is doing today."
Portugal were largely underwhelming, with goalkeeper Rui Patricio called upon to make a stunning second-half save from Younes Belhanda to preserve their advantage.
Santos admitted his team had ridden their luck but brushed aside complaints from Morocco counterpart Herve Renard that Ronaldo's goal should have been ruled out due to a push by Pepe.
"I think, for Morocco, it was an unfair result but that's football. If you score you can win but I am not happy with the performance of my team," Santos said, before claiming Pepe was the victim, not the aggressor in the goal.
"Who pushed Pepe? It was a Moroccan and then Pepe defended himself against a Moroccan player.
"The first foul was by a Moroccan. There was no refereeing mistake, it could have been a penalty."