Samoa full-back Paul Williams has escaped a suspension following his sending off in Friday's Pool D loss to South Africa.
The New Zealand-born 28-year-old was red carded for striking Springbok flanker Heinrich Brussow.
A judicial officer has stated that the incident was at the "lower end of the scale of seriousness" and that Williams is now free to play.
A Rugby World Cup statement said: "The judicial officer found that there were compelling on-field and/or off-field mitigating features and a complete absence of on-field and/or off-field aggravating features.
"In particular he determined that the strike was an open-handed push, the contact was not heavy and there was no adverse effect on the victim player or the match."
Samoa's 2011 tournament is likely to be over as Wales need only one more point from their final game against Fiji tomorrow morning to qualify in second behind South Africa.
