Calliste has 18 points and Oregon beats No. 3 Arizona 64-57

As Oregon's Mike Moser looks on, rear left, teammate Johnathan Loyd battles Arizona's Rondae Hollis-Jefferson and Jordin Mayes, right, for a loose ball during the first half of an NCAA college basketball game in Eugene, Ore. on Saturday, March 8, 2014. (AP Photo/Chris Pietsch) (The Associated Press)

Oregon's Waverly Austin, left, fouls Arizona's Aaron Gardon as he defends the basket with teammate Oregon's Mike Moser, right, during the first half of an NCAA college basketball game in Eugene, Ore. on Saturday, March 8, 2014. (AP Photo/Chris Pietsch) (The Associated Press)

Jason Calliste made the go-ahead jumper and free throw with 4:22 left and finished with 18 points as Oregon defeated No. 3 Arizona 64-57 Saturday for its seventh straight victory.

Johnathan Loyd added 16 points for the Ducks (22-8, 10-8 Pac-10) who greatly improved their chances of a bid in the NCAA tournament.

Aaron Gordon had 21 points for the Wildcats (28-3, 15-3), who had already clinched the Pac-12 regular-season title heading into next week's conference tournament in Las Vegas.

The Ducks won 13 straight to start the season and got ranked as high as No. 10, but then they lost five straight to tumble out of the poll and fall in the Pac-12 standings.

But Oregon's six-game winning streak put them back in the conversation for a possible NCAA tournament bid and gave them their fourth straight season with at least 20 victories.