Oregon’s top three returning players from last season’s NCAA Tournament team made the difference in the Ducks’ 87-75 win over rival Oregon State on Monday in a nonconference game at Eugene, Ore.Nate Bittle led Oregon (4-0) with 24 points, Jackson Shelstad scored 22 and Kwame Evans Jr. had his best game of the young season with 16 points and 14 rebounds.Shelstad drilled two key 3-pointers as part of his 12 second-half points. One was a step-back from the top of the arc for a 67-60 Ducks lead, and the other came in front of the Oregon bench in the corner to make it 78-67 with 5:02 left.Bittle followed the latter trey with a dunk, when he was wide open for a pass from teammate Devon Pryor going down the lane after getting behind the Beavers’ defense.The Ducks won for the ninth straight time over the Beavers (3-1) and outrebounded Oregon State 38-27.Isaiah Sy led Oregon State with 14 points. Yaak Yaak and Josiah Lake II added 10 each.Oregon led by 12 early in the second half, but Oregon State chipped away and trailed 61-58 after Sy was fouled on a 3-point try and made all three free throws with 10:53 to play.