Ronaldo, who has not scored an international goal in 16 months, rattled a post with a blistering early strike, but that was as close as his side came to snatching victory on a frustrating afternoon at the Nelson Mandela Bay Stadium.
Even Didier Drogba's arrival as a second-half substitute, to the delight of a crowd of 37,034, could not separate the sides as each attempted to gain the upper hand in Group G ahead of their respective encounters with Brazil.
Ivory Coast boss Sven-Goran Eriksson was boosted ahead of kick-off when he was able to name captain Drogba among his substitutes just 10 days after he had broken a bone in his arm.
The Swede could not have failed to be satisfied too by the time he welcomed his players back to the dressing room at half-time with an opening 45 minutes in which they had more than matched their opponents.
However, for all that, they could have been behind after Ronaldo saw his spectacular 30-yard strike come back off the upright with keeper Boubacar Barry beaten just 11 minutes in.
In a frustrating first half for the European side, Ronaldo was booked along with defender Guy Demel as they went nose to nose after the winger had gone to ground all too easily, with Demel and Didier Zokora, who had himself earlier been cautioned for unceremoniously upending the Real Madrid star, leaving him in little doubt as to their thoughts on the matter.
But where he was Portugal's only real outlet with Danny and Liedson largely anonymous in a three-man frontline, Ivory Coast showed real enterprise before the break.
Gervinho, leading the line in Drogba's absence, proved a real handful, and with Aruna Dindane and Salomon Kalou similarly progressive, the Portuguese were repeatedly stretched.
That said, keeper Eduardo did not have a single save of any note to make in the opening 45 minutes with speculative efforts from Siaka Tiene and Ismael Tiote requiring only a watching brief.
Eduardo finally had to get his hands dirty two minutes after the restart when Gervinho blasted a shot across him, and Paulo Ferreira did just enough to prevent Kalou from reaching Dindane's cross seconds later.
The Braga keeper was called upon once again with 54 minutes gone when Yaya Toure cut inside at pace and fed Kalou, although the Chelsea man side-footed straight at Eduardo from the edge of the box.
Portugal coach Carlos Queiroz immediately replaced Danny with winger Simao, but it was Deco who provided the 58th-minute cross for Liedson's looping header, which was plucked out of the air by Barry.
Drogba's World Cup began in earnest when he replaced Kalou with 66 minutes gone, but with heavy rain falling, it was Portugal who finished the stronger, although crucially, without coming close to making the breakthrough.
Even Didier Drogba's arrival as a second-half substitute, to the delight of a crowd of 37,034, could not separate the sides as each attempted to gain the upper hand in Group G ahead of their respective encounters with Brazil.
Ivory Coast boss Sven-Goran Eriksson was boosted ahead of kick-off when he was able to name captain Drogba among his substitutes just 10 days after he had broken a bone in his arm.
The Swede could not have failed to be satisfied too by the time he welcomed his players back to the dressing room at half-time with an opening 45 minutes in which they had more than matched their opponents.
However, for all that, they could have been behind after Ronaldo saw his spectacular 30-yard strike come back off the upright with keeper Boubacar Barry beaten just 11 minutes in.
In a frustrating first half for the European side, Ronaldo was booked along with defender Guy Demel as they went nose to nose after the winger had gone to ground all too easily, with Demel and Didier Zokora, who had himself earlier been cautioned for unceremoniously upending the Real Madrid star, leaving him in little doubt as to their thoughts on the matter.
But where he was Portugal's only real outlet with Danny and Liedson largely anonymous in a three-man frontline, Ivory Coast showed real enterprise before the break.
Gervinho, leading the line in Drogba's absence, proved a real handful, and with Aruna Dindane and Salomon Kalou similarly progressive, the Portuguese were repeatedly stretched.
That said, keeper Eduardo did not have a single save of any note to make in the opening 45 minutes with speculative efforts from Siaka Tiene and Ismael Tiote requiring only a watching brief.
Eduardo finally had to get his hands dirty two minutes after the restart when Gervinho blasted a shot across him, and Paulo Ferreira did just enough to prevent Kalou from reaching Dindane's cross seconds later.
The Braga keeper was called upon once again with 54 minutes gone when Yaya Toure cut inside at pace and fed Kalou, although the Chelsea man side-footed straight at Eduardo from the edge of the box.
Portugal coach Carlos Queiroz immediately replaced Danny with winger Simao, but it was Deco who provided the 58th-minute cross for Liedson's looping header, which was plucked out of the air by Barry.
Drogba's World Cup began in earnest when he replaced Kalou with 66 minutes gone, but with heavy rain falling, it was Portugal who finished the stronger, although crucially, without coming close to making the breakthrough.
