Teams: Iran vs Portugal
Venue: Mordovia Arena
Mordovia Arena will host Portugal and Iran in their last match in group B, with both sides fighting to scale through to round of 16. Portugal need at least a point while Iran need three points from the game.
Portugal are presently placed second in the group with four points while Iran, who pipped Morocco 1-0 before falling against Spain, lie in third place with three points.
Portugal's all four goals in the tournament have come through Ronaldo and they will once again rely heavily on the talismanic striker if they want to make it to the second round. So, Iran's primary objective will be to stop Cristiano Ronaldo from scoring in this game.
They will look to boss the midfield in order to launch attacks and score goals. Portugal need an improved performance, having sometimes struggled to keep the ball and carve out chances.
Asia's number one team, Iran benefited from a late own goal by Morocco to get their World Cup opener win. They lost to Spain in a hard-fought battle. They have so far been impressive in defence and their defenders will have to, once again ,come out with spirit to restrict Ronaldo from scoring.
Iran coach Carlos Queiroz has already declared the match against Portugal as the most interesting and important match.
"We go for it, with great belief and great determination to try to win the game," Queiroz said. "When we arrived, no-one gave us a chance, but we still fight for our dreams," he added.
IR Iran: Ali Beiranvand; Ehsan Haji Safi, Morteza Pouraliganji, Ramin Rezaeian, Majid Hosseini; Saeid Ezatolahi, Vahid Amiri, Omid Ebrahimi, Karim Ansarifard, Mehdi Taremi; Sardar Azmoun
Portugal: Rui Patricio; Pepe, Jose Fonte, Raphael Guerreiro; Cedric Soares, William Carvalho, Joao Moutinho, Bernardo Silva, Joao Mario; Goncalo Guedes, Cristiano Ronaldo
Did you know?
The two teams have faced each other at the World Cup once before. That was in the Germany 2006 group stage, with Portugal running out 2-0 winners and a certain youngster by the name of Cristiano Ronaldo getting the second goal.
Iran's Masoud Shojaei was also at the tournament, but did not play that day.