OKLAHOMA CITY -- At first, it was hard to tell just how far Jocelyn Alo's monster home run traveled.

Alo's two-run blast in the fifth inning helped Oklahoma defeat Alabama 7-3 on Sunday night to advance to the championship series. It cleared the center-field seats, the cameras and a slow-pitch fence that is 300 feet to center to give the Sooners a 4-1 lead.

"That disappeared into the darkness really fast,'' Oklahoma coach Patty Gasso said. "I've seen her hit some, but I'd say that's probably right there with some of the furthest I've ever seen from anyone, and she's usually the one that hits it further than I've ever seen.''

Alo said she knew it was a home run right away.

"Sweet," she said. "It felt effortless.''

Oklahoma (57-4) will play UCLA in a best-of-three series starting Monday. Oklahoma seeks its third Women's College World Series title in four years and its fourth championship this decade. UCLA has 12 national titles, but none since 2010.

"We have got to have some crazy fight,'' Gasso said. "I know both teams are a little worn out. You have a chance -- there's two teams that have a chance to win a national championship. There's no such thing as tired, no such thing as hurt. Nothing like that.''

UCLA qualified when Rachel Garcia's walk-off homer in the 10th beat Washington 3-0 on Sunday. Garcia also threw 179 pitches and struck out 16 to earn the win.

Alabama (60-10) would have had to beat Oklahoma twice on Sunday to advance because Oklahoma beat the Crimson Tide on Thursday and the Sooners were unbeaten in the double-elimination format. In the first game, Alabama pinch-hitter Caroline Hardy singled to score Kloyee Anderson in the bottom of the eighth to clinch a 1-0 win for the Crimson Tide.

"That's what you dream about doing,'' Hardy said. "You dream about it as a little kid getting a walk-off hit, your team coming and doing a hug in the middle of the field.''

In the second game, Oklahoma got its offense going early. Caleigh Clifton doubled to score Sydney Romero, then Clifton scored on a wild pitch to give the Sooners a 2-0 lead in the first inning.

Oklahoma started Giselle "G'' Juarez, but she was replaced in the second inning shortly after giving up a solo homer to Reagan Dykes. Juarez had pitched 7 2/3 innings in the first game, and Gasso wanted to get just a little bit out of her before going to Mariah Lopez. It worked -- Lopez got the win after giving up two runs in 4⅓ innings.

Alo's homer gave the Sooners a cushion, but Skylar Wallace's two-run homer in the sixth cut Oklahoma's lead to 4-3.

Oklahoma's Nicole Mendes answered in the bottom of the sixth with a two-run homer that gave the Sooners a 6-3 edge. Grace Lyons tacked on a solo blast that made it 7-3.

"Once Jocelyn hit that home run, it was like a spark was ignited,'' Mendes said. "Once this team gets a spark, it's really hard to stop us. Definitely made us a lot more free, kind of got the ball rolling.''

Alabama felt it proved it was better than its No. 8 seed. The Crimson Tide beat Florida, Arizona and Oklahoma in the tournament -- all teams seeded higher than them.

"Well, I just think with 60 wins, beating the people that we beat here, we definitely proved our No. 8 seed,'' Alabama coach Patrick Murphy quipped. "We were worthy of that, for sure. Possibly a little bit more.''

In the first game on Sunday, Alabama freshman Montana Fouts pitched a shutout against Oklahoma a day after she shut out Arizona. Murphy said she has a bright future.

"I think the sky's the limit because she's just really learning how to pitch,'' Murphy said. "When she gets different movement pitches, really spinning in the right direction, up, down, in and out, she's going to be really, really good."