STANFORD (AP) — No quarterback in the country has had to manage expectations the way Josh Nunes has had to this season succeeding the NFL's No. 1 overall pick.

In the last three weeks alone, the redshirt junior quarterback outplayed Heisman Trophy hopeful Matt Barkley to upset Southern California, shouldered the blame of a stunning loss at Washington and rallied No. 17 Stanford (4-1, 2-1 Pac-12) from a two-touchdown deficit for a thrilling 54-48 overtime win against Arizona that quieted questions about Andrew Luck's successor

"It's not that we learned," Cardinal coach David Shaw said. "It's maybe that other people learned he's a tough kid. He bounces back, he doesn't listen to the noise. He's steady."

Nobody said filling Andrew Luck's shoes would be easy.

Fair or not, Stanford's streakiness this season has been tied directly to its new quarterback. Both are still somewhat of an unknown heading to seventh-ranked Notre Dame (5-0) on Saturday, with the exception of one undeniable fact.

As Nunes has gone so far, so has Stanford.

Nunes overcame a pair of first-half interceptions to throw for 215 yards and two touchdowns in a 21-14 win against USC, including a 37-yard strike to tight end Zach Ertz for the winning score, vaulting the Cardinal to as high as No. 8 in The Associated Press college football poll.

He followed that by completing 18 of 37 passes for 170 yards and an interception in Stanford's 17-13 loss at Washington, often underthrowing receivers on short routes or misfiring completely. The offense converted 5 of 18 third downs, never scored a touchdown and looked lost for the first time since Luck left.

Fans and media began to criticize Nunes enough for Shaw to open his weekly news conference defending his quarterback. Nunes rewarded his coach's loyalty with his best performance yet, throwing for 360 yards and two touchdowns and running for 33 yards and three more scores against Arizona on Saturday.

"I definitely have confidence now," Nunes said. "The guys up front did what they needed to do as well as the guys downfield. I definitely used last week (at Washington) as a stepping stone forward and learned a lot of things to work on. I feel like I did a better job this week, but there are a lot more things we need to correct."

Notably, consistency.

Coaches and teammates have insisted that, more than anything, Nunes needs time and experience to adjust to the starter's role. After all, he went almost four years since his last start at Upland High School in the Los Angeles area until beating out Brett Nottingham and Kevin Hogan this season.

Nunes has shown flashes of Luck-like ability to in big moments.

He scrambled for a pair of key first downs against the Trojans. On the final drive of regulation against Arizona, he ran for 16 yards on third-and-7 from midfield, threw 17 yards to Ertz on fourth-and-9 from Arizona's 20 and ran for the tying touchdown on a read option with 45 seconds remaining.

"If you told me a year ago that we'd call multiple run plays for Josh Nunes, I'd laugh at you," Shaw said. "The bottom line is he's a tough kid. He's not afraid of it. He doesn't back down from challenges."

The road ahead will not ease up any.

While Stanford has beaten Notre Dame by at least two touchdowns the last three seasons, this appears to be a more a difficult trip to South Bend. Not to mention matchups at No. 2 Oregon and a home date against No. 10 Oregon State later this season.

The Fighting Irish improved to 5-0 for the first time since 2002 with a 41-3 romp over Miami on Saturday. Notre Dame's 587 yards of offense was a season high, and its 376 yards rushing was its most since Nov. 11, 2000.

Asked if Nunes' turnaround performance against the Wildcats will do enough to quiet critics before Notre Dame, Shaw shook his head and smiled.

"Probably not," he said. "And once again, I don't care. He doesn't care. We're a team. We're tight in our locker room. We support him through everything, and he understands that. We hold him accountability for what his job is. But at the same time, we know he's more than capable. And I think he showed that."