Jordan Adams scored a team-high 15 points for the Bruins (24-8), who will advance to play the winner of the Arizona State and Stanford matchup in Friday's semifinal round. Travis Wear and Zach LaVine netted 14 points apiece, while David Wear added 11 points on 4-of-5 shooting from the floor.
Oregon (23-9) came up short despite a stellar performance by Joseph Young, who knocked down 6-of-11 attempts from beyond the arc en route to a game-high 29 points. None of Young's teammates managed to join him in double-figures.
Both sides played well offensively in the opening stanza as UCLA connected on 55.6 percent of its field goal attempts and the Ducks shot 54.2 percent from the floor. The Bruins also sank 4-of-6 tries from 3-point range before the break, which helped them take a 37-35 lead into the intermission.
Oregon was limited to 35.5 percent efficiency from the floor, including a 4- of-17 clip from 3-point range over the final 20 minutes of the contest. UCLA converted 11-of-14 attempts at the charity stripe in the second stanza to pull away for the 19-point triumph.
UCLA enjoyed a 34-29 edge in the rebounding battle and assisted 18 of its 30 makes from the floor.