Argentine Juan Cruz Mallia received a two-week suspension for a challenge that knocked South African Grant Williams unconscious in a Rugby Championship match, the Southern hemisphere rugby body Sanzaar said on Friday.
Full-back Mallia collided with scrum-half Williams just 10 seconds into the final-round fixture in Johannesburg last Saturday after the Springbok fielded the kick-off and cleared the ball.
The referee considered it a legitimate charge but the citing commissioner dissented leading to a probe by a Sanzaar judicial committee, which found it warranted a suspension.
"The act of foul play was reckless, with a high degree of danger and had a considerable impact on the victim player," committee chairman Nigel Hampton KC wrote in the findings.
Williams, making his first start for the reigning world champions after three appearances off the bench, was driven from the field on a stretcher.
Medical attention led to a quick recovery and later in the first half the scrum-half joined the South African replacements on a pitch-side bench.
Speaking after the Springboks edged the Pumas 22-21 to finish runners-up behind New Zealand, head coach Jacques Nienaber said Williams would be out of action "for at least two weeks".
The committee said it opted for a "low-range" sanction against Mallia, suspending him until 18 August.
"A mid-range sanction would be wholly disproportionate to the player's fault," Hampton wrote.
Mallia will thus be able to take part in the Rugby World Cup in France in September – but will miss a rematch against South Africa on Saturday, this time in Buenos Aires for a warm-up game.
South Africa, winners of the World Cup a record-equalling three times, will also play Wales and New Zealand before the global showpiece while Argentina face Spain in another warm-up match.