Andreas Avraam was Cyprus' hero as they deprived Portugal of victory in a staggering opening game of their Euro 2012 qualifying campaign in Guimaraes.
Both teams led twice as the game freewheeled from end to end, with first-half goals from Efstathios Aloneftis and Michael Constantinou cancelled out by Portugal's Hugo Almeida and Raul Meireles.
The home team led through Danny and Manuel Fernandes in the second period, but Yiannis Okkas and Avraam drew Cyprus level.
Portugal were caught by an early bolt from the blue as Aloneftis' low 20-yard drive found the corner of the net. Marinos Satsias failed to emulate his team-mate's long-range efforts and the hosts then quickly levelled as Almeida headed in Nani's cross in the eighth minute.
Cyprus were happy to let fly from range at any opportunity and Eduardo had to hold Konstantinos Makridis' strike before the visitors restored their lead in the 11th minute, Constantinou finishing low after the ball broke to him in the penalty box.
Fabio Coentrao and Meireles fired over as Portugal again looked to bounce back and Nani then drew a sharp block from visiting keeper Antonis Georgallides, who then held Miguel's 30-yard shot - still with just 20 minutes on the clock.
Meireles drew Portugal level for a second time in the 29th minute, the Liverpool newcomer beating Georgallides with a low drive from 20 yards.
Elias Charalambous blocked efforts from Danny and Manuel Fernandes before Satsias tested Eduardo from range as Cyprus eased the spell of pressure on their defence.
Portugal twice went close before half-time, Ricardo Carvalho heading Ricardo Quaresma's corner over before Georgallides tipped Fabio Coentrao's drive around the post.
Four minutes after the interval, Danny put his side in front for the first time when he headed in another Quaresma corner. The advantage lasted just seven minutes as Okkas fired home right-footed to
level matters at 3-3.
But Portugal almost immediately restored their lead, with Quaresma again the provider from a corner as Manuel Fernandes fired home.
Quaresma was denied the chance to add his own name to the scoresheet, Georgallides tipping over both his 25-yard effort and then Nani's free-kick.
Constantinou tested Eduardo but Portugal looked more likely to add to their lead, Quaresma denied by Georgallides before Liedson, on as a substitute for Danny, hit the post.
Constantinou curled a free-kick over and two Makridis corners came to nothing but Cyprus got their equaliser with two minutes remaining.
Constantinou's effort was fumbled up in the air by Eduardo and Avraam headed home the loose ball to earn a sensational point from a game which - with eight goals, chances galore and only a solitary booking, for Charalambous - represented everything to enjoy about football.