JP Pietersen scored a hat-trick of tries as South Africa bounced back from their shock loss to Japan with a 46-6 six-try, bonus-point victory over Samoa at Villa Park.
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The two-time World Cup winners learned lessons from the 34-32 Japan defeat in their opening Pool B match and overpowered Samoa in a hugely physical contest in Birmingham.
The Springboks were made to pay for spurning early shots at goal in their Brighton beating, but this time Handre Pollard took the points and Pietersen scored an opportunist try for a 17-6 half-time lead.
South Africa ruthlessly applied the pressure thereafter, with scrum-half Fourie du Preez outstanding in dictating the tempo.
Pietersen scored two more tries, Schalk Burger was rewarded for an impressive personal performance with a score, replacement hooker Schalk Brits touched down and Bryan Habana added a sixth.
Pollard finished with 14 points, while Michael Stanley's two penalties were all Samoa could muster in reply.
South Africa next play Scotland and the United States – sides who meet in Leeds on Sunday – and could yet top the pool and claim a more favourable quarter-final draw with two wins.
Samoa next play Japan, eager to respond from a defeat where their intent was stated from the start, with the physicality epitomised by flanker TJ Ioane's bone-crunching tackle on Springbok hooker Adriaan Strauss.
The Pacific Islanders were competitive at the breakdown and in the tackle, but were undone by their inability to relieve pressure, some indiscipline and Stanley's inaccuracy with the boot.
Earliere, Italy squeaked past a determined and inventive Canada 23-18 to keep alive their World Cup quarter-final hopes.
Tries from Michele Rizzo and Gonzalo Garcia plus 13 points from the boot of Tommaso Allan proved just enough for Jacques Brunel's men to avert an upset, but they face a far tougher assignment next against Ireland on October 4.
Italy were made to work extremely hard for their unconvincing victory and the key moment was arguably the decision to disallow a Phil Mackenzie try for the Canucks in the 45th minute for a forward pass in the build-up, just after an excellent Matt Evans try had put them 15-13 in front.