EUGENE, Ore. (AP) A triple-double by senior Sabrina Ionescu, that's become almost routine. A big game by freshman Jaz Shelley, now that's new.

Shelley hit a school-record 10 3-pointers in his first start for No. 3, scoring 32 points in an 84-41 romp over UC Riverside on Monday.

Ionescu had 16 points, a career-high 18 rebounds and 12 assists in her NCAA-record 20th triple-double, and second of the season.

Shelley started for the Ducks (9-1) in place of an ailing Satou Sabally. The emerging star from Australia said she sensed a possible strong shooting game was possible after a morning practice in which she was on target.

Shelley scored 17 in Saturday's win over Long Beach State.

''I think I'm more comfortable now,'' Shelley said. ''When I'm on, I know my teammates are going to get me the ball.''

The chance to start ''was a huge opportunity. I definitely like to grab opportunities by the horns,'' she said.

Ionescu enjoyed the performance.

''We know how great of a shooter she is,'' Ionescu said. ''She puts in the work and with that comes a lot of rewards.''

Jannon Otto led the Highlanders (3-7) with 19 points. Riverside shot only 25%, a season low for an Oregon opponent.

The Ducks opened the third quarter on a 15-2 run, including a trio of 3-pointers by Shelley. She made five 3s in the period as Oregon took a 61-28 lead.

''We didn't do our defensive assignments in the second half the way we need to,'' Riverside coach Seyram Bell said, adding that Oregon is ''a really scary team and it's kind of like pick your poison'' on which Duck to defend.

About all that was left to be decided entering the fourth quarter was whether Ionescu would record double figures for assists. With six minutes left, she fed Taylor Chavez for a fastbreak layup and her 10th assist.

Both teams appeared to struggle with the morning tipoff time as Oregon led 17-9 after one quarter.

BIG PICTURE

UC Riverside: The Highlanders are 0-4 against Pac-12 opponents this season.

Oregon: The Ducks are 5-0 in home games, winning by an average of 43 points.

SHELLEY SHOTS

Shelley made her 10 3s in 14 attempts. She is shooting 16 of 26 in her past two games, including 15 of 22 on 3-pointers.

''Jaz has been coming,'' coach Kelly Graves said. ''Remember the name Jaz Shelley, she's a really good player.''

SABALLY SITUATION

Graves said Sabally is ''a little banged up.''He said she could possibly play in Oregon's next game, Saturday against Kansas State.

OREGON THIEVERY

The Ducks had 14 steals, which Graves said was the most by Oregon in his six seasons. That was among 20 turnovers by Riverside.

UP NEXT

UC Riverside is at Southern Utah on Thursday.

Oregon plays host to Kansas State on Saturday. After that, the Ducks begin their Pac-12 schedule.

UC Riverside Highlanders

UC Riverside Highlanders

Ionescu posts triple-double as Oregon routs UC Riverside