The Portuguese, who celebrated a 2-0 aggregate win over Bosnia at the same venue in their 2010 World Cup play-off, dominated proceedings but were almost caught napping late in the game after a subdued home side finally came to life.
Portugal had the upper hand in the opening stages with Cristiano Ronaldo and Nani looking lively on either flank, but failed to create any clear-cut chances as their final pass kept going astray on a bumpy surface littered with holes.
The consistently unpredictable and awkward bounce of the ball forced Helder Postiga to fire his close-range volley high over the bar several minutes before Sanel Jahic blocked a stinging Ronaldo shot from 12 metres.
The Portuguese continued to press after the interval and Ronaldo missed an excellent chance in the 51st minute, scuffing his shot wide from 10 metres after a defence-splitting through ball hit a clot of mud in front of him.
Postiga then curled his shot from the heart of the penalty box just wide of the far post as the Bosnians began to tire and needed several last-gasp clearances to keep the visitors at bay.
Bosnia's in-form Manchester City striker Edin Dzeko had a quiet game and attempted his first shot on goal only in the 71st minute, blazing his effort from 20 metres high and wide.
SQUANDERED CHANCES
Second-half substitute Vedad Ibisevic injected attacking spirit into the home side but squandered Bosnia's best two chances in the closing stages, the first when he sliced the ball wide from seven metres after a poor first touch.
The striker was then put through by a delightful Miralem Pjanic pass but shot over the bar when he had only keeper Rui Patricio to beat.
Both coaches, Bosnia's Safet Susic and Paulo Bento of Portugal, agreed the poor surface affected the quality of play by two usually entertaining sides.
"We did not score a goal although we deserved it for what we did here. Portugal played on a pitch which UEFA should not have allowed but we tried to do the best we could," Bento told Portuguese television.
"Both sides had their chances, I was confident there would be at least one goal in the game but a very difficult pitch made scoring a tall order," Susic told Bosnia's BHT television.
"Portugal are a great side, they showed their class throughout the game and caused us a lot of problems.
"I am sure they will have the same level of respect for us after this game because they know we can score away from home and I think we have a realistic chance of reaching next year's finals in Poland and Ukraine."
He added: "They will be happy with this result as much as we are and the tie is likely to go down to the wire. Whatever happens in the return leg, I am proud of the players for coming this far."
