Returning home after Saturday's 2-1 defeat by Denmark, Northern Ireland will have expected to make use of the Windsor Park advantage.
Yet, after former heroes Jonny Evans and Steven Davis were honoured just before kick-off, the crowd were quickly silenced by an efficient Iceland outfit.
Fresh off beating Scotland 3-1 at Hampden Park, the visitors took any sting out of the opening exchanges without asking much of Pierce Charles in the home goal.
In of their own spells in possession, the hosts' efforts will have felt disappointingly similar to their defeat in Copenhagen as, too often, they were quickly caught on the ball and turned over.
The spark that brought the game to life came with O'Neill switching Conor Bradley from right wing-back into a more attacking position, with the Liverpool man almost making an instant impact.
With his side suddenly more threatening, it was only moments later when, nine minutes before half-time, Price picked the ball up, drifted inside from the left and curled a low effort into the bottom corner.
The West Bromwich Albion man, who scored a hat-trick on this ground against Bulgaria in October, celebrated his ninth international goal - the same number as George Best and Norman Whiteside netted for the country.
A team transformed, Northern Ireland came close to doubling their lead in first-half injury time when Ross County striker Ronan Hale was denied a debut goal by the crossbar and Price fired the rebound over.