Fueled by key hits and clutch defensive plays, Arizona beat UCLA, 5-2, Sunday in a semifinal game in front of 3,648 at Hall of Fame Stadium.
Arizona (63-3) will face Cal State Northridge (52-9), a 4-2 winner over Oklahoma State, in today's championship game at noon.
The game will be televised live for the first time in the event's 13-year history. It will be shown on ESPN 2.
Weiman (21-9), who allowed six hits, three walks and four earned runs, was still tired from her two losers' bracket victories over Illinois-Chicago and Utah on Saturday.
"I felt pretty tired today after yesterday," Weiman said. "I was really struggling with the energy factor. I didn't feel at my best today at all."
After Arizona scored single runs in the second and third, UCLA tied the game in the third.
Nicole Odom, who reached on an error, went to second on a sacrifice and advanced to third on Janae Deffenbaugh's single, scored the Bruins' first run on a bloop single by Ginny Mike, who had two hits.
Deffenbaugh later scored on Jen Brundage's bases-loaded sacrifice fly to left, which fell short of the fence by about three feet.
Trailing, 4-2, in the fifth inning, Mike singled with one out. Kelly Howard followed by ripping a liner into the right-center field gap. But right fielder Andrea Doty made a shoestring grab and then threw out Mike at first for a double play, which ended the inning.
"The way things had been going, I pretty much expected her to catch it," Howard said.
Doty's grab was par for the course, said UCLA Coach Sharron Backus.
"The score was not indicative of the game. I knew we'd come out battling," Backus said. "A few inches here and there and who knows?"
Arizona's Jenny Dalton capped the scoring by ripping a 2-2 pitch 225 feet, over the center field fence for a 5-2 lead.