South Africa captain Siya Kolisi has been cleared to play against Wales this weekend after escaping sanction for an apparent headbutt on Scotland's Peter Horne.
Replays showed Kolisi appear to strike Horne with the back of his head in the 31st minute of the Springboks' narrow 26-20 at BT Murrayfield on Saturday, with the TMO deciding at the time not to bring the incident to the attention of referee Romain Poite.
After a further review of the footage in the aftermath of the game, World Rugby announced on Monday that Kolisi's action stopped just short of being a red card offence.
A World Rugby statement read: "Having reviewed the video angles, the Citing Commissioner determined that there were mitigating factors which meant that the action did not meet the red card threshold, including the player being illegally prevented from re-joining the play by Scotland's Peter Horne and the moderate force of the strike to the side of the head.
"The match officials did not see the incident at the time on the field of play."
Kolisi, 27, has however received a Citing Commissioner Warning for his part in the incident.
The decision not to sanction the Springboks captain has already prompted a bemused response from Saturday's opponents Scotland, with full-back Stuart Hogg questioning why the TMO failed to refer the action to Poite.
"These things happen but you question what the TMO is doing," Hogg told the BBC. "He can have a look three or four times, or as many times as he wants. The unfortunate thing was we got a good outcome on the back of that phase of play, so they didn't look back at it.
"Peter Horne is a hard bugger and just managed to get on with it. He didn't whinge about it.
"I asked Pete 'was that a legit head-butt?' and he said he felt he was head-butted. But it has happened. We can't do anything about it now."
South Africa face in form Wales in Cardiff on Saturday, with head coach Rassie Erasmus warning his players to expect their toughest game of the autumn internationals so far.