The Highlanders will be seeing yellow. They picked up a yellow card late in the first half and it proved costly. The Chiefs ran in two tries with the extra man to set up a 42-12 win in Hamilton tonight. The Highlanders’ playoff prospects are now only held together by an impossibly thin mathematical thread. They also lost star winger Caleb Tangitau to a serious-looking knee injury in the final moments of the game. It was the Chiefs’ 250th win and their ninth in a row against the Highlanders. The loss has left the Dunedin-based team stranded in seventh place — one spot outside of the top six — with one round-robin match remaining. That game is against competition front-runners the Hurricanes in Wellington. They are toast. And the Chiefs took a bite, scoring six tries. The home side dominated the opening exchanges. Loose forward Simon Parker made a monster tackle on halfback Adam Lennox to set up a turnover for the Chiefs. They battered away but the Highlanders’ defence held up.…