BERKELEY, Calif. -- No. 1 California battled back from a two-run deficit to tie the game 2-2 in the bottom of the sixth against No. 2 Arizona State before senior Valerie Arioto unleashed a two-run, walk-off homer in the bottom of the seventh to defeat the Sun Devils 4-2.

The Golden Bears (49-3, 20-2 in the Pac-12) are now just one win away from the Pac-12 Championship though if ASU (45-6, 17-3 in the Pac-12) wins the final two games, the Sun Devils will claim the Pac-12 title.

The Sun Devils drove in their two runs -- one in the fourth and one in the sixth -- off eight hits to take a 2-0 lead. The Bears worked ASU starter Dallas Escobedo for two earned runs off six walks and four hits. In the bottom of the sixth, Escobedo walked in both of the Cal runs, knotting the game at 2-2.

Cal's all-time single-season and the Pac-12 leader in homers, Arioto sent out her 22nd homer of the year with one away in the bottom of the seventh.

Cal's Danielle Henderson improved to 30-0 thanks to her eight-strikeout performance. Escobedo lasted 5.4 innings in which struck out as many as she walked -- six in each category. Mackenzie Popescue (7-2) relieved her in the bottom of the sixth, suffering the loss after the seventh-inning bomb.