Oregon 68, Oklahoma State 55: Damyean Dotson scored 17 points and Arsalan Kazemi had 11 points and 17 rebounds as the 12th-seeded Ducks scored the upset in the NCAA Tournament second-round game in San Jose, Calif.Dominic Artis scored 11 of his 13 points in the second half and recorded a team-high four steals for Oregon, which will play fourth-seeded Saint Louis on Saturday. Carlos Emory added 12 points off the bench for the Ducks (27-8) in their first NCAA Tournament appearance since 2008.Markel Brown scored 16 points to lead fifth-seeded Oklahoma State (24-9). Marcus Smart, the Big 12 Player and Freshman of the Year, finished with 14 points, nine rebounds, five steals and four assists for the Cowboys, but shot 5-for-13, and 4-for-8 at the free throw line. Oklahoma State committed 10 of its 14 turnovers in the first half and gave up 11 of the 14 offensive rebounds, opening the door for Oregon to build a 37-26 halftime lead. The Ducks initially gained separation when Oklahoma State went 6:19 without a field goal midway through the opening half, allowing them to move out to a seven-point lead.The Ducks scored the first four points of the second half to go up by 15 and they maintained a double-digit advantage the rest of the way.GAME NOTEBOOK: Since the tournament expanded to 64 teams in 1985, a No. 12 seed has beaten a No. 5 seed 38 times, including three times in the last two seasons. The last time all four No. 5 seeds advanced through the first round was 2007. … Oklahoma State fell to 12-4 in NCAA Tournament openers. … Oregon had six turnovers in the first 5:51 and 18 for the game.