A late equalizer by Helder Postiga earned Portugal a 1-1 draw against Northern Ireland in a World Cup qualifying game Tuesday, sparing the home team's blushes as Cristiano Ronaldo racked up his 100th international appearance.

Postiga rescued his team in the 79th, tapping in from short range just as the Portuguese were poised to record their second defeat in a row following last week's 1-0 loss in Russia.

Niall McGinn put Northern Ireland ahead from a counterattack on the half-hour, and the visitors looked likely to upset its more celebrated opponent.

Ronaldo, who became only the third Portuguese player to collect 100 caps and is the youngest to reach that milestone, had few chances in a match in which the Euro 2012 semifinalist was again uninspired in attack.