Williams received a “citing commissioner warning” for a high tackle in the 40th minute of the Chiefs' 21-13 loss to the Wellington Hurricanes on Saturday.
Such warnings are issued for incidents which are very close to, but do not quite meet the threshold for a red card citing, which would usually result in a ban.
Williams will therefore be available for the New Zealand derby against the Highlanders in Dunedin on Saturday, which will decide which of the two teams goes through to the semi-finals.
Saturday's other wildcard playoff pitches the Stormers against the ACT Brumbies in Cape Town and the South African side look likely to lose the services of young back Robert du Preez after he was cited for a spear tackle.
The 21-year-old, son of a former Springbok scrumhalf of the same name, was making his Super Rugby debut in Saturday's 34-12 loss to the Sharks when he was yellow carded in the 76th minute for dangerous play.
Given the current crackdown on such tackles du Preez is almost certain to be banned, although he would have been an unlikely starter against the Brumbies in any case given the Stormers rested 14 first choice players for the Sharks match.
The Canberra-based side have some concerns about a far more important member of their team after flanker David Pocock failed a concussion test during Saturday's defeat to the Canterbury Crusaders.
Coach Stephen Larkham said he expected the African-born Wallabies forward, who scored his eighth try of the season on Saturday, would be cleared to play at Newlands.
“Poey came off for a concussion test, so he's on a six-day, return-to-play protocol, but he should be fine,” Larkham told reporters in Canberra.
“Six days back to playing is Friday and he can partake in training on the Wednesday, so he should be fine.” – Reuters
Original source: Sonny Bill avoids tackle ban