Cristiano Ronaldo’s 74th international goal was enough to earn Portugal victory over hosts Russia in the Confederations Cup.

The Real Madrid forward’s early header secured a 1-0 win at Moscow’s Spartak Stadium and left Fernando Santos’ side second in Group A, behind Mexico on goal difference.

Only the goalkeeper Igor Akinfeev, winning his 100th cap, denied Portugal victory by a greater margin as he made vital saves from Ronaldo and André Silva either side of half-time.

Russia were poor before half-time and although they improved after it, they were repeatedly forced back on the break as they committed men forward in search of an equaliser.

Cristiano Ronaldo heads the ball beyond Igor Akinfeev to score Portugal’s winning goal after just eight minutes. Photograph: Chris Brunskill Ltd/Getty Images

Ronaldo, making his 141st appearance, needed eight minutes to make his mark, although the opening goal was far from all his own work. With Russia attempting to sit deep and deny Portugal space in midfield, Raphaël Guerreiro found room on the left flank and delivered an inviting cross to the far post, where Ronaldo made the most of defender Fedor Kudriashov’s misjudgment to head home.

Ronaldo proved the main threat throughout the first half as the hosts offered little going forward, and he tested Akinfeev with a 25th-minute free-kick before forcing the keeper to block with his legs seven minutes later.

Russia might have been level as the half-time whistle approached but the striker Fedor Smolov could not adjust his feet in time to steer Aleksandr Golovin’s cross on target.

Akinfeev kept Russia in it when he clawed away Silva’s 50th-minute header from close range, and he was in the right place at the right time to repel Cédric Soares’ long-range effort nine minutes later.

Russia, who beat New Zealand 2-0 in their opening fixture, belatedly launched their push and might have been level just after the hour when Alexander Samedov’s teasing cross was only fractionally too high for Smolov in the middle.

Ronaldo passed up a glorious opportunity to extend his side’s lead just past the hour when he headed wide from Andre Gomes’ cross as Portugal broke at pace.

It was Russia who finished strongly with Aleksandr Bukharov appealing in vain for a last-gasp penalty after going down in the box, before the defender Georgy Dzhikya headed inches over Rui Patricio’s crossbar deep into injury time.

Mexico 2-1 New Zealand

In the day’s other Group A game, Mexico came back from a half-time deficit to beat New Zealand 2-1 and end their opponent’s hopes of reaching the semi-finals. Leeds United striker Chris Wood had put New Zealand ahead with a tidy finish just before the interval, but Mexico equalised after 54 minutes, Raúl Jiménez turning Javier Aquino’s low pass from the left into the roof of the net.

Oribe Peralta celebrates after scoring Mexico’s second goal. Photograph: Buda Mendes/Getty Images

Mexico dominated the second half and earned victory when Oribe Peralta scored from close range after 72 minutes, again after good work down the left from Aquino. There was controversy late in the game, with several players involved in a skirmish after Michael Boxall’s foul on Héctor Herrera. Referee Bakary Gassama consulted a television monitor and his video assistant referees, before Boxall, Herrera and Mexico’s Diego Reyes received yellow cards.

Mexico’s win puts them top of Group A, level with Portugal on four points. The result also means Russia will almost certainly need to beat Mexico in their final group match on Saturday to reach the semi-finals, with Portugal facing already eliminated New Zealand.