TUCSON, Ariz. -- Danielle O'Toole threw a one-hit shutout on her senior day and Jessie Harper went 3-for-3 with two homers and five RBI, helping the Wildcats beat No. 23 Arizona State 8-0 in five innings and win the series over their rivals for the second straight year.
 
Arizona hit four home runs in an 11-batter stretch between the third and fourth innings, breaking open what was a 0-0 game heading into the third. Mo Mercado and Harper hit back-to-back solo homers in the third before Harper hit a grand slam in the fourth and Alyssa Palomino followed with a solo homer of her own.
 
The offensive explosion ended what had been a frustrating series for the Wildcats. Arizona, which entered the weekend second in nation in scoring at nearly eight runs per game, had been held to six total runs in the first two games.
 
While the offense put on a show, so did O'Toole, who improved to 26-3 on the season with her one-hit masterpiece. O'Toole fanned five and walked three in the complete game effort.
 
The Wildcats (47-5, 17-4 Pac-12) will head to UCLA next week with their first conference championship since 2007 on the line.
 
After wasting two-on opportunities in the first and second innings, Mo Mercado and Jessie Harper hit back-to-back solo homers to give Arizona a 2-0 lead after three innings.
 
In the fourth, Carranco and Hughes led off with back-to-back singles before a walk to Katiyana Mauga loaded the bases with one out. The Sun Devils walked Mercado for her second RBI of the game, before Harper hit a grand slam to left-center for her fifth multi-homer game in 2017. The five RBI tied a career high. Palomino followed with a solo homer and O'Toole slammed the door in the fifth to give the Cats a run-rule victory.
 
Up Next: Arizona will conclude the regular season at UCLA next weekend. The Cats and the Bruins meet Friday-Sunday in Westwood.
 
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