CORVALLIS, Ore. -- Notre Dame coach Muffet McGraw didn't think her unbeaten team had been tested until facing Oregon State on Sunday.
Kayla McBride scored 20 points, Natalie Achonwa added 16 points and eight rebounds, and the second-ranked Irish remained perfect with a 70-58 victory over the Beavers.
"It's a huge win for us," McGraw said. "It's great to be behind and have a close game at the end and see how we respond."
Notre Dame (11-0) scored the final five points of the first half to pull to 33-31 at halftime for its first deficit at the break this season. The Irish then got the first six points of the second half to take the lead for good.
McBride said the road game before a hostile crowd of more than 4,000 felt like an NCAA tournament matchup.
"I know we have a target on our back and everybody is going to bring us their best game," she said.
Oregon State certainly did that.
"They played so hard, and I respect that a lot," McBride added.
Jamie Weisner scored 18 points to lead the Beavers (8-4), and Ruth Hamblin added 12 points, eight rebounds and a school record-tying nine blocks.
"We had a lot of turnovers down the stretch. We totally could have won that game," Weisner said.
Beavers coach Scott Rueck felt his team got some needed confidence despite the loss.
"This team competed for 40 minutes, just laser focus," Rueck said. "We know we can play with anybody."
Oregon State didn't trail until Ali Gibson's 3-pointer with 13:06 left in the first half.
Hamblin's putback had stretched the Beavers' lead to 33-26 with 55 seconds left in the opening half. The Irish then used its 11-0 spurt to take the lead for good.
Notre Dame began the day leading the nation in field goal shooting (52.2 percent) and 3-point shooting (44.9 percent), but the Irish shot 36 percent overall in the first half and 1-for-6 on 3s.
"Definitely credit their defense," McGraw said. "We got good looks, but we really missed the shots that normally we'll make."
With 1:25 left, however, Ariel Braker got a steal off an inbounds play for Oregon State, and McBride made a jumper to push the lead to 66-58. Braker blocked Weisner on the Beavers' next possession.
McGraw said defense was critical to the comeback.
"When we contained the ball and didn't give them driving lanes, we were able to really shut them down," she said. "They couldn't kick it out to wide open shooters."
Sophomore Jewell Loyd, last year's national freshman of the year, had 10 points for the Irish -- 8.5 below her team-leading average coming in.
The Irish, who have reached the Final Four each of the last three years and title games in 2011 and 2012, are off to their best start since 2009-10, when they began 15-0.
Notre Dame's next game is Jan. 2 against South Dakota State.
Weisner, a sophomore guard, entered the contest as the Beavers top scorer at 14.9 points per game. OSU has a young team, with four underclassmen starters.
Sunday's game was the start of a tough stretch for the Beavers, who open Pac-12 play next week with games against No. 23 California and No. 4 Stanford.