The Real Madrid star was unmarked at the back post, where he rose to head Raphael Guerreiro's cross past Russia keeper Igor Akinfeev and into the net after just eight minutes.

The loss placed the hosts' chances of qualifying for the semifinals in peril, having taken three points from their opening two matches with co-leaders Mexico to play on Saturday.

But Cherchesov backed his back line after the match, reminding reporters the four-time Ballon d'Or winner is a difficult player to contain.

"We lost him but it's not just us, look at how many Ballons d'Or he has!" Cherchesov said.

"We let them cross it into the box and then finish it."

There were some suggestions that Russia were intimidated by the moment early, playing in front of a packed home crowd before nearly scratching out an equaliser in the final 45 minutes.

"We were certainly not nervous," he said.

"The game did not go according to our wishes but we changed things during the break. We kept losing the ball in the first half and did not launch any attacks.

"In the second half we changed things round a bit and we had several good chances but unfortunately they did not produce any goals."

Russia sit third in Group A with three points, one behind co-leaders Portugal and Mexico, the latter of which they must defeat to have a chance at advancing.

"I don't think there's anything better than to rely on yourself," Cherchesov said.

"We have a clear understanding of what needs to be done. The next game is only three days away and we need to know who is ready.

"Sometimes little ailments come out after the second or third match but I don't think we have any injuries."