New AC Milan signing Andre Silva should lead Portugal's attack in Saint Petersburg, where Portugal will be the heavy favorites.
It was a typically efficient performance from Portugal who never looked in real danger despite a sluggish start.
But Bernardo Silva picked up a knock on that play, which eventually saw him exit the game.
New Zealand goalkeeper Stefan Marinovic, who helped Unterhaching win promotion from the German fourth division last season, kept the score down with a superb second-half display.
"We have to be better and more consistent, stronger in both ways".
Mexico continued to push for a third goal in pursuit of topping the group, but two late goals in the group's other game gave Portugal a cushion to finish top on goal difference. New Zealand finished bottom of the group after losing all three games.
The hosts wanted a penalty after Zhirkov fell inside the area in the sixth minute, but he was barely touched by the Mexican defender and the referee let the play continue.
Ronaldo brushed off allegations of tax evasion in Spain with man-of-the-match performances in the 2-2 draw with Mexico and 1-0 victory over hosts Russian Federation, when he scored the victor. Hirving Lozano subsequently completed the Mexican comeback after the interval.
The hosts' pressure soon told, though, as the opening goal arrived after 25 minutes.
Mexico's Hector Herrera, top, and his teammates celebrate their side's first goal during the Confederations Cup, Group A soccer match between Mexico and Russia, at the Kazan Arena, Russia, Saturday, June 24, 2017.
Advancing from the group with European champion Portugal and Gold Cup victor Mexico was seen as a hard task from the start, but an opening victory against New Zealand had left Russian Federation in position to make it to the semifinals despite a loss to Portugal in the second match.
Mexico defender Nestor Araujo equalised in the 30th minute with a looping header. Portugal sits in second position now, level with Mexico on both points and goal difference, but behind by one on goals scored.