The Blues have narrowly beaten the Chiefs 16-13 in their Super Rugby derby at a rain-drenched Waikato Stadium.
The Chiefs scored two tries to the Blues' one but lost by 16 points to 13.
Luke McAlister kicked 11 points for the Blues, including the match-winning 72nd minute long-range penalty.
The former All Black added two other penalties and a conversion of Jared Payne's try, which he had set up with a grubber kick, to give the Auckland-based side the lead in the New Zealand conference of the southern hemisphere's competition.
Elsewhere the New South Wales Waratahs won 29-22 at the ACT Brumbies in the Australian derby, while the Queensland Reds routed South African's Cheetahs 41-8 in Brisbane.
The champion Bulls have finally won at their Pretoria fortress, beating compatriots the Lions 30-23.
Another South African side, the Stormers, beat the Western Force 51-16 in Cape Town.