The world No. 1's men's volleyball team started its Olympics with aplomb on Friday when Brazil swept Tunisia 3-0 at Ariake Arena in Tokyo.
The defending Olympic gold winners, Brazil converted 33.7% of their spike points in winning 25-22, 25-20, 25-15.
Brazil coach Renan del Zotto got 21 spike points between Wallace de Souza and Douglas Souza.
Tunisia is ranked 17th in the world by FIVB.
Italy, who won silver in Rio, dodged a terrific comeback bid from Canada to win 3-2 earlier Friday.
Saturday action saw world No. 9 Argentina take a surprising first set from ROC, but the Russian Olympic Committee's team rallied from that 25-21 setback to win three-straight sets 25-23, 25-17, 25-21.
Japan swept Venezuela in three sets as well, winning 25-21, 25-20, 25-15.