Andi Sullivan scored twice and goalkeeper Jane Campbell picked up her 34th career shutout as No. 3 Stanford topped Arizona 4-0 on Thursday night in Tucson.

The Cardinal improve to 15-1-1 on the season and 8-1 in Pac-12 Conference play, while Arizona drops to 7-9-1 and 2-7 in the Pac-12.

With the game still scoreless in the 39th minute, Sullivan collected a pass from Jordan DiBiasi at the top of the 18-yard box and ripped it to the left of diving UA goalkeeper Lainey Burdett to give the Cardinal a 1-0 lead just before the first half ended.

“We lost the ball in our half and our backline didn’t step quick enough to the shooter,” Arizona head coach Tony Amato said. “And it was Andi, who’s in the full [United States] Women’s National Team, and if you let her shoot from there, she’s probably going to have a good shot at scoring.”

Even though Stanford went to halftime up 1-0, the first half was relatively even. Both teams finished with eight shots, and Stanford was limited to one corner kick, while Arizona had none.

Arizona nearly scored the first goal of the game in the 31st minute when forward Charlotte Brascia had a one-on-one with Campbell after breaking through Stanford’s backline.

However, Brascia’s shot sailed just over the crossbar.

“The first half we definitely had some chances,” Amato said. “The game plan, tactically, looked like it could be effective; we were just going to have to grind through some moments where they had possession and hope that when the chances came our way that we could bury them, and it didn’t happen on the night. Even at halftime we still felt like we were still in the game—it was just going to take maximum, maximum effort—and that kind of died of when they scored the second goal.”

The Cardinal tacked on that second goal in the 65th minute, when Kyra Carusa dropped a pass into the middle of the box for Michelle Xiao, who knocked it into the back of the net.

“They got the ball wide and they scrambled down that side and lost players in the box and they were able to tuck it away from close range,” Amato said.

Sullivan tacked on a third goal for Stanford via a penalty kick in the 71st minute to make it 3-0, then Ryan Walker-Hartshorn added a fourth and final goal in the 75th minute.

“I think in the first half we really wanted it more,” said UA defender Samantha Falasco, who Amato mentioned was ‘very, very good’ in the game. ”But I don’t know what happened in the second half. [Stanford] just showed up and they were ready to play, and we didn’t give our best effort out there like we should’ve.”

The teams each had eight shots a piece in the first half, but the Cardinal outshot the Wildcats 11-2 in the second half.

“I think in the first half we connected more passes and got more on the attack and had more people getting forward, and then in the second half I feel like we were more set on defending,” said UA midfielder Cali Crisler. “But we needed to keep attacking to get more chances.”

Brascia, Gabi Stoian and Kennedy Kieneker led the Wildcats with two shots a piece, while Hannah Stevens and Laura Pimienta each had a shot on goal. In total, four of the Wildcats’ 10 shots were on frame, but Campbell saved them all.

Arizona returns to action Sunday when it hosts No. 18 Cal in the Wildcats’ last home game of the season.

Kickoff at Mulcahy Stadium is set for 11 a.m., and Senior Day festivities will be held before the match.

You can follow Ryan Kelapire on Twitter