Junior forward Bri Pugh had six shots, three on target, and goalkeeper Abby Steele made five saves as Oregon falls to 2-3-0 on the season.
"We put up 17 shots and nine corners, and unfortunately didn't get a goal there," said head coach Kat Mertz. "I thought we created a lot of chances in the first half to go up by at least one, if not two. We take this as a growing lesson, and give Hawai'I credit; they're a scrappy team that was fighting for the first win."
Oregon took 11 shots in the first half, its second highest shot output of any half this season, and created many opportunities to take a lead.
The Ducks and Rainbow Wahine entered the second half in a scoreless stalemate as both goalkeepers were keen to shut down any scoring chances.
Hawai'I went on to break the stalemate in the 61st minute after earning a corner kick. Hayden Gibson sent the corner into the box, and Kenui Storm flicked the ball across the box with her back heel. Pascua calmly set the ball into the back of the net from the six-yard box.
The Ducks put Hawai'I on their heels late in the second half, looking for the equalizer. Pugh, a native of Highlands Ranch, Colo., generated most of the scoring chances for the Ducks, with six shots and three shots on target.
Oregon had six shots on the second half with 17 in the game, its highest shot count since taking 20 in the season-opener. Despite a threatening attack, goalkeeper Monk Berger and the Hawai'I defense held on for a narrow victory.
Pugh led the way on offense, followed by Riley Smith, Shanelle Simien and ShayLee Miner, who each took two shots.
"Bri had a good game," said Mertz. "I probably left her on a little too long in the second half, but when a forward is feeling it I'm going to let her go. I thought she was going to be able to get one for us."
The Ducks will look to rebound on Sunday, hosting UC Irvine at 1 p.m. (PT) at Papé Field.