David Healy ended his miniscoring drought to keep Nothern Ireland in with a shout for a place in South Africa.
The striker has made just one substitute appearance since his summer move to Sunderland but he still has an eye for goals in the green of Northern Ireland.
They endured half an hour of frustration before Healy took Grant McCann's pass, skipped past his man and stabbed in his 35th international strike.
Boss Nigel Worthington said: "I'm delighted for David. It was good for him and helped to settle us down as well."
McCann, Kyle Lafferty and Steven Davis scored the other goals to give the Irish their biggest win in 13 years.