By Daniel Alvarenga
LISBON (Reuters) - Cristiano Ronaldo struck the first blow in his personal duel with Zlatan Ibrahimovic when his late flying header gave Portugal a 1-0 win over Sweden in the first leg of their World Cup qualifying playoff on Friday.
Neither of the big-name players contributed much to a feisty encounter until Ronaldo stooped to meet Miguel Veloso's pinpoint cross from the left with an intelligent header in the 82nd minute.
Until then Ronaldo had struggled against a massed Swedish defense, wasted two free kicks by firing into the wall and been booked shortly before his goal for a foul on goalkeeper Andreas Isaksson as his frustration boiled over.
Sweden had several chances in the first half before Portugal took control after the break at the Luz stadium, gaining the upper hand for Tuesday's second leg in Stockholm.
"We would have been very happy with a draw," Sweden coach Erik Hamren told TV4. "We played a good game defensively, the goal was unnecessary, we were careless with that cross."
Portugal could have gone ahead in the opening minutes when Raul Meireles put Joao Moutinho clean through only for the Monaco midfielder to shoot into the side-netting.
The Swedes then enjoyed a brief period of dominance and came close when Johan Elmander just failed to hit the target from a pinpoint cross by right back Mikael Lustig.
"We created a great early chance and Sweden hit back. But in the second half it was one way for us," Portugal coach Paulo Bento told reporters.
"It was an important step to reach the World Cup but not yet decisive."
Ibrahimovic was mostly left alone up front, making him easy prey for the Portuguese defense.
His only real flash of inspiration was a dummy that created a clear shooting chance for Sebastian Larsson, whose effort was turned away by Rui Patricio.
"We managed to counter Sweden's direct football. I don't think their football will change much in their home leg, maybe perhaps press a bit higher," Bento said.
Portugal were also hugely relieved to see Kallstrom blast a close-range free kick narrowly wide.
The hosts then won a flurry of corners which produced that apart from a Ronaldo header over the bar.
Sweden fielded a very experienced side, with more than half of their starters in their thirties, many of them with the last chance to play a World Cup.
Portugal coach Paulo Bento, in turn, stuck to his routine line-up, with Veloso and Moutinho the midfield combatants while Nani and Helder Postiga completed the attacking trio alongside Ronaldo.
Portugal dominated the second half although they did not create many clear cut chances until Ronaldo's goal. That brought them to life and Ronaldo headed against the bar in the dying minutes.
"It was an important goal that gave us the win," Ronaldo, who scored his 44th goal for the national team, told Portuguese radio.
"We could have scored one or two more but the advantage raises our spirits for the away match. But it's not done yet, it remains 50/50 chances for both teams, in my opinion."
Portugal have qualified for the past seven international tournaments in succession, the preceding two via the playoffs.
(Reporting by Daniel Alvarenga; Editing by Brian Homewood and Stephen Wood)