Technically Grievous as he appeared on Hyporri would actually be weaker than in Season 1 of TCW, despite his flashy badassery. So Malak does have a rather prominent chance in this scenario, though the fight should be pretty close.
However, I would reckon that the OP is attempting to direct us toward Grievous's strongest incarnation, which he mistakably believes to be his appearance on Hyporri, so I would imagine Grievous from just before RotS. In that case scenario he definitely outguns the likes of an unamped Malak.
Originally posted by Eminence
Not a field, but stasis was briefly used on Bane in Rule of Two, I think by either Worror or Farfalla.