The defending champions and one of the title favorites both lost in Super Rugby on Friday, ensuring nothing can be taken for granted as the competition enters the final four rounds of the regular season.
Title holders the Highlanders went down 27-20 to New Zealand rivals the Hurricanes after a last-minute try by the 'Canes, the team the Highlanders beat in last season's final.
Flanker Ardie Savea marked his return from a disciplinary suspension with two tries, including that 80th-minute match-winner, for the Wellington-based Hurricanes.
Australia's New South Wales put in a big second-half performance to beat the much-fancied Chiefs 45-25, with Wallabies internationals Michael Hooper and Israel Folau both scoring braces. The Chiefs' slip-up gave the Crusaders a chance to open a lead at the top of the standings when they play the Blues on Saturday.
In a battle of two new teams in Super Rugby in Friday's last match, Argentina's Jaguares had two first-half red cards and a late yellow card - another indication of their terrible discipline this season - in their 29-22 loss to South African strugglers the Southern Kings.