New Zealand found it "bloody tough" to get the job done against Argentina, number eight Ardie Savea admitted.
Yoann Huget scored a double as Toulouse overcame Clermont Auvergne 24-18 in the Top 14 final at Stade de France.
Clermont Auvergne will face Toulouse in the Top 14 final after an emphatic 33-13 defeat of Lyon in Bordeaux.
Toulouse saw off La Rochelle 20-6 to claim the first spot in the Top 14 final.
Racing 92 boosted its hopes of qualifying for the European Champions Cup by thrashing bottom side Perpignan 52-14.
Top 14 leader Toulouse saw its unbeaten league run end at 14 games courtesy of a 25-10 loss to Toulon, which played most of the second half with 14 men.