RIO DE JANEIRO, June 16 — Cristiano Ronaldo gets the opportunity to upstage fellow superstar Lionel Messi when Portugal open their World Cup campaign tomorrow with a mouth-watering clash against fellow European heavyweights Germany.

Having dethroned Messi as World Footballer of the Year, Ronaldo, who has been battling a left knee injury, declared himself 100 per cent fit to play in the Group G match in Salvador, comfortably the stand-out fixture of the day.

“I’d like to be 110 per cent, but I am at 100 percent and ready to help the national team,” said the 29-year-old Real Madrid star.

“Obviously, I would like to play without pain, but in my entire career I have always had injuries and knocks to deal with, but I am ready to play.”

Three-time champions Germany beat Portugal 3-1 in the third place play-off at the 2006 World Cup, 3-2 in the 2008 European Championships quarter-finals and 1-0 in the first round of Euro 2012.

Other statistics weigh against Ronaldo as Germany have won all of their World Cup opening matches since 1990.

Germany have a number of injury doubts going into the eagerly-awaited game.

But goalkeeper Manuel Neuer will return to duty after overcoming a strained shoulder and midfield star Bastian Schweinsteiger will play even though he was helicoptered to a hospital on Saturday for a knee scan.

In the group’s other game tomorrow, 2010 quarter-finalists Ghana face the United States in Natal having knocked out the Americans in the last 16 four years ago.

African champions Nigeria, who have taken just two points from six matches in their last two appearances at the World Cup, face three-time Asian champions Iran in Curitiba in Group F.

Iran determined

“Iran has faced difficulties off the pitch but we want to make our point on the pitch,” said Iran’s 61-year-old Portuguese coach Carlos Queiroz who cut his teeth as Alex Ferguson’s right-hand man at Manchester United.

“The economic and political situation is a complete disadvantage for the team but the players are very determined.”

Argentina went top of Group F at Rio’s famed Maracana this morning when Messi scored a sparkling individual goal and created another in a 2-1 win over Bosnia.

The Barcelona superstar produced a trademark moment of magic on a night that also saw France beat Honduras 3-0, with the help of the first goal decided by goal-line technology.

Karim Benzema’s strike early in the second half cannoned back off the inside of an upright across the goal at Porto Alegre’s Beira-Rio Stadium.

Honduras goalkeeper Noel Valladares’ tried to scoop it clear but the German-manufactured GoalControl goal-line technology system signalled the ball had crossed the line, prompting Brazilian referee Sandro Ricci to whistle for a score.

There was a brief delay as Ricci consulted his fourth official while Honduras manager Luis Fernando Suarez angrily protested but Valladares’s own-goal stood.

World Cup chiefs said Monday they will modify the way goal-line technology rulings are communicated to fans after the Honduras controversy.

FIFA spokeswoman Delia Fischer said the “unique” nature of the incident — the ball striking a post and rebounding into the Honduran goalkeeper — had caused the confusion.

“Yesterday’s situation was quite unique,” she said, because it had triggered two animations.

“We are working to make it more clear. We will modify so you just see the ‘goal’ decision,” Fischer said.

“There were no mistakes yesterday. It all worked as planned. However we are working to modify it to make much clearer for fans inside the stadiums.” — AFP