The Blues held on to the top spot in the New Zealand conference with a 10-15 Super Rugby victory over the Highlanders in Dunedin.
The Highlanders scored the only try of the match but the Blues kicked five penalties and led throughout the match.
The Highlanders game plan was disrupted early in the match when first-five Tony Brown went off injured which saw fullback Robbie Robinson taking over at 10.
The Highlanders finished within seven points of the Blues and their losing bonus point moves them above the Crusaders with matches to come in the round.
Discipline cost the Highlanders dearly as they lost two players -Jarrad Hoeata and Aaron Smith to the sin-bin.
Their best spell of the match ironically came straight after half time when they scored their try whilst being down to 14 men.
Blues centre Luke McAlister kicked all of his team's points but was injured late in the game and had to limp off five minutes from time.
McAlister kicked five penalties from six attempts and put the visitors into a 0-9 lead at half-time.
Inspired by long-serving lock Kurtis Haiu, who was diagnosed with bone cancer during the week, the Blues racked up their fifth straight win over the Highlanders the surprise package of this year's Super 15 Rugby tournament.
The Highlanders kept the Blues tryless but failed to show the form which provided a surprise win over the Crusaders last week and paid the price for poor discipline in a tightly-fought first half.
Conceding nine penalties in the first 40 minutes, the Highlanders gifted the Blues 63 percent of possession, relying on dogged defence as their attack faltered.
With lock Jarrad Hoeata sinbinned just before half-time, the Highlanders appeared set for a torrid 10 minutes after the break.
However, midfield back Matt Saunders upped the tempo after the restart, with a line break that set the scene for Robbie Robinson to give the Highlanders the only try of the match.
The setback failed to rattle the Blues, who maintained the pressure even as the Highlanders closed the deficit to 12-10, sealing the win with a penalty in the 65th minute.
Any hopes of a Highlanders comeback were snuffed out when Aaron Smith was sinbinned for a spear tackle on Luke McAlister four minutes from time.
Final Score Highlanders 10 Blues 15
Tries - R. Robinson
Pen - R Robinson
Con - R Robinson
Cards - Jarrad Hoeata (40) yellow, Aaron Smith (75) yellow
Pen - L McAlister 5
Referees: Chris Pollock (New Zealand)
Assistant referees: Garratt Williamson (New Zealand), Kane McBride (New Zealand)
Television match official: Ben Skeen (New Zealand)
Highlanders:1 ,Jamie Mackintosh (C) 2 , Jason Rutledge 3 , Chris King 4, Jarrad Hoeata 5 , Josh Bekhuis 6 , Adam Thomson 7 , Alando Soakai 8 , Nasi Manu 9 , Jimmy Cowan (VC) 10 ,Tony Brown 11,Siale Piutau 12 , Ben Smith 13 ,Kendrick Lynn 14 ,G Kade Poki 15, Robbie Robinson
Replacements: 16. Mo Schwalger 17. David Te Moana 18. Tom Donnelly 19. Nick Crosswell 20. Aaron Smith 21. Matt Saunders 22. James Paterson.
Blues: 15 Isaia Toeava, 14 Joe Rokocoko, 13 Jared Payne, 12 Luke McAlister, 11 Rene Ranger, 10 Stephen Brett, 9 Alby Mathewson, 8 Peter Saili, 7 Luke Braid, 6 Jerome Kaino, 5 Ali Williams, 4 Anthony Boric, 3 John Afoa, 2 Keven Mealamu (c), 1 Tevita Mailau.
Replacements: 16 Tom McCartney, 17 Pauliasi Manu, 18 James King, 19 Chris Lowrey, 20 Toby Morland, 21 Benson Stanley, 22 Lachie Munro.