The SeaHorses Mikawa ran into a red-hot Tochigi Brex squad on Saturday afternoon.
The reigning champion Brex, winners of seven in a row entering the series opener, came up short, falling 81-77 to Mikawa.
Kosuke Kanamaru sparked the SeaHorses (25-8) with 32 points, including 11 of 11 at the foul line. No other player attempted more than six free throws.