Jordan Petaia, 19, capped his long-awaited international bow with a try as Australia claimed a bonus-point win in Pool D.
Leinster's 21-year-old hooker Ronan Kelleher ran in a hat-trick in their thrashing of the Ospreys, while the Scarlets saw held off Glasgow.
Jordie Barrett will demonstrate his versatility by stepping in to take over as fly-half when New Zealand play minnows Namibia.
Lewis Moody says Agustín Creevy's dig over England's style could "fan the flames" for Eddie Jones' side against the Pumas.
Jacques Brunel has stuck with his rotation policy for France's match against Tonga - a fixture that produced a huge World Cup shock in 2011.
South Africa put 14-man Italy to the sword to put one foot in the quarter-finals, but Rassie Erasmus says there was room for improvement.
Ruthless South Africa moved to the top of Pool B by dishing out a seven-try hammering to Italy.
Eddie Jones is looking for England to show they can handle the step up in quality as they prepare to face Argentina and France.
New Zealand lock Brodie Retallick is set to make his return from injury against Namibia.
Japan will bid to make it three wins from three matches when they tackle Samoa in Toyota City on Saturday, and Michael Leitch is recalled.