Portugal has drawn 1-1 against minnows Iceland in their opening Group F clash of Euro2016.
Birkir Bjarnason, who equalized five minutes after the restart, canceled out Nani's first half strike.
Portugal dominated for the majority of the game and had a number of opportunities to increase their lead after Fenerbahce winger Nani had swept them into the lead on 31 minutes.
Cristiano Ronaldo, aiming to become to first player to score in four European Championships, struggled to make his mark throughout, with the 31-year old failing to convert a chance in both halves.
The two sides began the match at the Stade Geoffroy-Guichard in Saint Etienne with vastly different expectations.
Iceland, a nation of 330,000 people, was happy to be competing in their first ever-major tournament. Portugal, on the other hand, was aiming to stamp their authority on a group that was perceived prior to the tournament as one of the easiest at Euro2016.
With a team containing their 'golden generation', Iceland started spritely, and was nearly rewarded for their energy early on. Swansea's Gylfi Sigurdsson made a great run into the box but his shot was well saved by Portugal's Rui Patricio.
Portugal soon found their groove and began dominating possession. Their first chance came through Nani after 15 minutes of play. The Fenerbache forward should have scored from a Ronaldo cross, had it not been for a fine save from Iceland's Hannes Halldorsson.
Soon after, Ronaldo made a piercing run through the Icelandic defence and was picked out by Pepe's long ball, but he was unable to make any contact before it skidded into the hands of Halldorsson.
It didn't take much longer for Portugal to open their Euro2016 account. On the 31st minute mark, a neat one two between Andre Gomes and Vieirinha saw Gomes freed up on the right wing and his pinpoint cross was met by the unmarked Nani, who calmly passed the ball past Halldorsson.
The second half resumed just as the first had concluded, with Portugal dominating possession and a second goal in their sights but much to their dismay, it was Iceland who opened the second half scoring.
On the 50th minute mark, Gudmundsson whipped in a deep cross from the right wing and some porous marking left Bjarnason wide open at the back post. The Basel midfielder took the opportunity with both hands as he volleyed home from six yards out.
Fernando Santos' side was in shock and it took them twenty minutes to find the rhythm they established in the first half.
Ronaldo missed a sitter when he found himself free in the six-yard box with five minutes remaining. The Portuguese skipper seemingly tried to push his header back across goal but could only manage to direct it straight at Halldorsson. The same can be said up the other end of the ground, as Finnbogason found the space in the Portugal box but was only able to fire his shot straight at Patricio.
A historical night for Iceland as they secured there first ever points at a major tournament but Portugal will be left ruing what could have been.
Euro2016 – Group F
Portugal: 1 (Nani 31')
Iceland: 1 (Birkir Bjarnason 50')
Stade Geoffroy-Guichard, Saint Etienne – 38,742