Down four points at halftime, Stanford coach Johnny Dawkins was confident his team could deliver a strong effort in the second half.
It didn't happen.
Instead, the Cardinal collapsed under their own mistakes as No. 23 Oregon turned the tight game into a rout, winning 77-66 on Saturday.
Stanford (16-12, 7-8) committed 10 of its 17 turnovers in the second half and star forward Dwight Powell, plagued by foul trouble, was ineffective at both ends of the court.
"It was a four-point game at halftime so I thought both teams were playing very well," Dawkins said. "We were comfortable. We knew we could come out in the second half and regroup and make a run."
Powell led the Cardinal with 16 points and Josh Huestis had 12 points and 13 rebounds.
But Johnathan Loyd had his best game of the season for the Ducks (22-6, 11-4) with 15 points and nine assists to keep Oregon tied with Arizona atop the league standings.
Carlos Emory led the Ducks with 19 points and Arsalan Kazemi also scored 15 for Oregon, which gave Oregon coach Dana Altman his 600th career win.
E.J. Singler added 12 points and Tony Woods had nine points and nine rebounds.
"Lots of guys played well but Johnny was the guy who stirred the drink," Altman said.
Loyd, making his ninth start in place of injured point guard Dominic Artis, made 6 of 8 shots for a season high in points and he also set a career high in assists.
It was a much different performance than his 0-for-6, no-point effort in a 48-46 buzzer-beating loss to the Golden Bears on Thursday.
"It felt great tonight," Loyd said. "I needed it. My teammates had faith in me. They kept telling me they believed in me so I just stepped up."
Oregon led just 30-26 at halftime but outscored the Cardinal 11-4 early in the second half to go up 46-34 with 13:50 to play and Stanford never got closer than 10 points the rest of the way.
The Ducks shot a season-worst 27.6 percent against California in a 48-46 loss on Thursday and it looked like things were on the same tract when both Damyean Dotson and Singler air-balled shot attempts in the opening minutes against the Cardinal.
But after falling behind 14-7, Oregon heated up.
The Ducks scored eight straight, including two on a short jumper from Loyd that put them up 15-14 with 11:01 to play in the half.
Stanford regained its lead 3:09 before halftime when Huestis capped a 6-0 run with a rebound dunk to make it 24-23.
Loyd followed with a 3-pointer, and then dished to Kazemi for a dunk and made a pair of free throws to help Oregon take a 30-26 advantage at the break.
Powell was a force for the Cardinal in the first half, scoring 12 points on 4 of 6 shooting. But the junior forward also picked up his third foul right before halftime and then added his fourth two minutes into the second half attempting to block Woods from stuffing back a miss by Singler.
That sent the Cardinal's leading scorer and second-leading rebounder to the bench for a six-minute stretch and the Ducks took advantage, going on a 14-6 run to push their lead into double digits, 46-34.
"You want guys on your team to step up," Dawkins said. "We needed some guys at that point to really assert themselves and make some plays for us to kind of keep us in position to where we have a chance to get back in the game. Unfortunately . they kept gaining ground."
Oregon led 48-36 when Dawkins was hit with a technical with 10:13 to play for arguing a foul called against Cardinal guard Gabriel Harris.
Singler made one of the two free throws for the technical, then both free throws for the original foul call to put the Ducks up 51-36.
Oregon's lead grew to 24 points, 66-42, with 5:27 left to play.
The Ducks finished the game shooting 48.4 percent and made 25 points off Stanford's turnovers.
They also outscored the Cardinal 42-18 inside.
The Cardinal, who handed Oregon its worst loss of the season three weeks ago at Maples Pavilion, 76-52, shot just 37.7 percent overall and made only 4 of 17 3-pointers.