New Zealand found it "bloody tough" to get the job done against Argentina, number eight Ardie Savea admitted.
Leinster's class ultimately shone through as it defeated Munster 24-9 to set up a Pro14 final against Glasgow Warriors.
Glasgow Warriors kept their nerve to secure a bye to a home Pro14 semi-final, while Ospreys and Scarlets are set to battle for the final European Champions Cup place.
Iliesa Ratuva Tavuyara touched down and Tommaso Allan converted with the last play of the game as Benetton Treviso held Leinster in Dublin.
In-form Benetton Treviso moved up to second in Pro14 Conference B with a 57-7 rout of the Dragons and Cardiff Blues came roaring back to beat Edinburgh.
Leinster ultimately withstood a spirited Zebre to win 40-24 and go 22 points clear at the top of Pro14 Conference B.