Iceland's first game at a major tournament finals ended all square as they ground out a 1-1 draw with Portugal in Saint-Etienne.
In what was the final first-round fixture at this summer's European Championships, Fernando Santos' side controlled the first half and deservedly took the lead through former Manchester United winger Nani on 31 minutes.
But the Portuguese were unable to push on, and they were pegged back when Birkir Bjarnason emphatically volleyed the Icelanders level five minutes after the interval.
Iceland then produced a resolute defensive display as Portugal captain Cristiano Ronaldo failed to inspire his nation to victory in their Group F opener.
Portugal now head to Paris where they take on Austria on Saturday, when Iceland, buoyed by their positive result, take on Hungary in Marseille.
Iceland almost made the perfect start at the Stade Geoffroy Guichard as Swansea playmaker Gylfi Sigurdsson cut inside Danilo down the left, but his attempts to beat Patricio at his near post were thwarted by the Sporting Lisbon stopper on three minutes.
After Iceland's positive start, Portugal took firm control of the contest, retaining possession as they probed for an opener.
They were denied on 21 minutes when, after great work from Ronaldo, Nani headed straight at the legs of Hannes Thor Halldorsson. The Iceland stopper's goal was soon breached, though.
After Ronaldo twice failed to make the most of half chances, Nani rounded off a fine Portuguese attack, sweeping Andre Gomes' cross past Halldorsson at his near post shortly after the half-hour mark.
Portugal continued to dominate up to the interval but in the second half, they were punished on 50 minutes when Bjarnason drifted behind Vieirinha to thunder a volley from Johann Gudmundsson's cross past Patricio.
Again, the Portuguese rallied, with Nani unable to turn Vieirinha's cross home on 63 minutes, and Iceland still posed a threat on the counter when Bjarnason's whipped cross caused panic among the Portugal defence two minutes later.
Pepe was lucky to escape severe punishment for lashing out at Jon Dadi Bodvarasson on 68 minutes after he was checked by the Iceland striker.
Nani was a whisker away from notching his second of the evening when he glanced Raphael Guerreiro's in-swinging free-kick fractionally wide on 71 minutes.
Ronaldo then spurned his clearest opening of the game when he head Nani's cross straight at Halldorsson five minutes from time, before substitute Alfred Finnbogason almost snatched the points with a rasping drive which Patricio parried over the bar.
A flurry of late Ronaldo free-kicks were then dealt with by the Icelanders as they held on for a valiant point on their major tournament bow.
Portugal: Rui Patricio, Vieirinha, Pepe, R Carvalho, Guerreiro, Danilo, Joao Mario, Moutinho, Gomes, Nani, Ronaldo.
Used subs: Eder, Sanches, Quaresma.
Iceland: Halldorsson, Saevarsson, Sigurdsson, Arnason, Skulason, Gunnarsson, Sigurdsson, Gudmundsson, Bjarnason, Sigthorsson, Bodvarsson.
Used subs: Finnbogason, Bjarnason.
Man of the Match: Aron Gunnarsson.