OKLAHOMA CITY — Tammy Williams and Garland Cooper hit back-to-back home runs in the eighth inning as Northwestern beat top-seeded UCLA, 3-1, yesterday, knocking the Bruins out of the Women's College World Series.

In a best-of-three championship series beginning today, fourth-seeded Northwestern (50-13) will face second-seeded Arizona, a 6-0 winner over eighth-seeded Tennessee last night. Arizona (52-11) lost 1-0 to Tennessee earlier in the day.

Northwestern's win came after UCLA's Kristen Dedmon provided late-inning dramatics. Dedmon, who drove in the winning run with a pinch-hit single in the 2004 championship game, again came off the bench to force extra innings with a two-out, RBI single in the bottom of the seventh.

Williams and Cooper responded with consecutive home runs off Anjelica Selden (35-7) to put Northwestern in position to play for the NCAA title for the first time in school history.

Eileen Canney (26-7) struck out six in a six-hitter, and Jamie Dotson added a home run off Selden in the second inning for Northwestern.

UCLA finished 50-9.

Arizona, which has won seven national titles, will be making its 11th championship-round appearance in 18 trips to the World Series, but its first since 2002.

In the second Arizona-Tennessee game, Alicia Hollowell (30-5) limited the Volunteers to two singles while striking out 14 and walking none.

In the earlier game, Monica Abbott pitched a two-hitter for Tennessee, which finished the season 61-12.