Portugal were held to a goalless draw by the Republic of Ireland to set up a showdown with Serbia for top-spot in group A.

The former European champions had scored 16 goals during their five-game winning streak across all competitions but could only muster two shots on target during a tough night in Dublin. 

Cristiano Ronaldo had a number of chances but the Manchester United attacker could not break the deadlock in Thursday's clash.

The visitors, who saw Pepe dismissed late on for two bookable offences, and Serbia both sit on 17 points with one game remaining as the latter travel to Lisbon for a winner-takes-all decider.

The Republic of Ireland made a slow start, but really should have taken the lead on the stroke of half-time but Chiedozie Ogbene could only head over from close range.

Stephen Kenny's men continued industriously after the interval and almost punished Matheus Nunes' concentration lapse when Josh Cullen curled into Rui Patricio's hands.

Ronaldo, who later fired narrowly off target, then nodded wide following Silva's cross before the hosts saw Enda Stevens whip over from Ogbene's inviting delivery.

The visitors, who had Pepe dismissed for a second bookable offence after catching Callum Robinson with his hand, managed to hold on for a point despite the hosts thinking they had found a late winner through Matt Doherty, Will Keane's foul on Patricio cutting short the celebrations.