Victoria Vivians led the way with 17 points, while Morgan William added 14 points and Chinwe Okorie chipped in 11 points. Okorie also added six rebounds as the Bulldogs moved to 5-0 with a fourth victory away from the Humphrey Coliseum.
Vivians moved past the 1,200-point mark for her career and into 11th place in the MSU record book.
"Oregon has some really great players," MSU head coach Vic Schaefer said. "They have a bunch of competitors. I knew this would be a knock-down drag-out. I was disappointed in some of our mental mistakes. Sometimes, we didn't follow the scouting report and didn't switch out.
"This game was not a letdown for us. You have to give credit to the opponents. We are now the hunted. We are learning about the role. In the third quarter, we took their best shot and responded. I am really proud of that."
The Bulldogs held a 13-9 lead with back-to-back baskets from Dominique Dillingham and Ketara Chapel. After Oregon (4-1) tied the contest back up at 13, MSU seized control with a 7-0 run, capped by an old-fashioned 3-point play from Vivians.
Oregon closed back within a single point twice in the early stages of the second quarter. The Bulldogs pushed the lead to 30-23 on a 6-0 run. The run was capped by two free throws from Roshunda Johnson.
The Bulldogs took a 39-30 halftime lead on a basket by Okorie with 42 seconds left.
In the opening half, the Bulldogs shots 62.5 percent from the floor, hitting 15-of-24 shots from the field.
Oregon closed within two at 44-42 with 6:00 left in the third quarter. Vivians then followed with back-to-baskets for a 49-42 lead. Oregon was held to one field goal in the final 4:14 of the quarter, as MSU led 53-47 entering the final round.
In the fourth quarter, the Bulldogs continued to excel on the defensive end, stretching the lead to a game-best 10 points at 67-57 on a three by Dillingham.
"We will see a ton of zone this year," Schaefer said. "We made some bad decisions in the second half, but we will work at it and get better at it. Playing on consecutive nights will help this team."
For the contest, the Bulldogs hit 27 of 52 shots from the field (51.9 percent), 4 of 11 shots from 3-point range (36.4 percent) and 17 of 22 shots from the foul line (77.3 percent). The Ducks hit 23 of 52 shots from the field (44.2 percent), 5 of 18 shots from 3-point range (27.8 percent) and 12 of 16 shots from the foul line (75.0 percent).
MSU held a 28-24 rebounding advantage. The Bulldogs had 13 assists and 14 turnovers, while the Ducks had 12 assists and 16 turnovers.
Oregon received 14 points apiece from Lexi Bando and Sabrina Ionescu. Matie Cazorla had 11 points. Bando had a team-high six rebounds.
MSU will face San Jose State at 7 p.m. CT Saturday in the second day of the tournament. That contest will be broadcast on WLZA-FM 96.1.