Ireland did enough to beat world champion South Africa 19-16 in an arm wrestle at Lansdowne Road on Saturday to justify its ascent to No. 1 in the rankings.
Ireland broke a 6-6 halftime deadlock with two tries in four minutes early in the second half, the first from a lineout maul by flanker Josh van der Flier and then a more expansive counterattack score from left wing Mack Hansen.
Ireland led 16-6 at that point and appeared set to see the game home, but South Africa bit back through replacement forward Franco Mostert and wing Kurt-Lee Arendse, whose try in the left corner with three minutes to go threatened an upset in Dublin.
Ireland didn’t let it happen and continued its impressive recent record at Lansdowne Road, where it has won three straight against the Springboks.
The result gave Ireland more confidence after it won an historic test series in New Zealand in July. It also struck a psychological blow for the Irish with the teams set to meet in the pool stage at next year’s Rugby World Cup in France.