"We are kind of a bit short at the moment," Gatland said.
Wales flattered in the first half to lead 23-3, a comfort they used in the second half to cut down their errors and limit Argentina's threat. The Welsh finished with two converted tries that spoke to their speed and power. Leigh Halfpenny padded the four tries with eight successful goalkicks, missing only once.
Nicolas Sanchez kicked both penalties for Argentina, hit the post with another, and was short with a dropped goal attempt, but while the Pumas gave the ball plenty of air, the support play was lacking and the Welsh defense was staunch.
Wales scored two tries in the first half. The first was opportunistic and the second a perfectly executed planned move.
In the eighth minute, Sanchez was surprised by a pass from flanker Julio Farias Cabello, juggled it and knocked it into the hands of Wales scrumhalf Mike Phillips, who sped 75 meters to score.
While Justin Tipuric was in the sin-bin for an off-the-ball tackle, Argentina couldn't take advantage, but Wales scored with Halfpenny's second penalty.
Halfway through the half, Alun-Wyn Jones tapped lineout ball down to Phillips, who drew the flankers out and passed inside for North to charge through a gaping hole 30 meters out. North easily beat the last defender for his 13th test try.
Wales took nearly another half an hour to score its third try. From quick scrum ball, Halfpenny joined the backline and fed left wing Liam Williams, who fended off his marker and found No. 8 Toby Faletau inside to run in untouched.
Then with 13 minutes to go, Wales showed off a rolling maul to power over Ken Owens, only four minutes after he'd replaced hooker Richard Hibbard.
