Nigel Worthington's men have fallen by the most number of places, while England remain in sixth position and World Cup finalists Spain and Netherlands lead the way
Nigel Worthington's men, who have won only one of their last 17 games including international friendlies, and none of the European Championship qualifiers, fell to 65th in the rankings.
Meanwhile, Craig Levein's side beat the Ulstermen but were unable to obtain a better ranking, as they plummeted to 66th position.
England remain unmoved as they hold on to sixth place, while Brazil move up two places to third. World Cup finalists Spain and Netherlands remain at the top, occupying the first and second spot respectively.
The biggest rise was by Israel and Belgium, as both nations upped their standing in world football by 25 places each to occupy the 33rd and 37th places respectively.