STANFORD, Calif. -- Stanford's season-opening loss to Northwestern is getting more and more difficult to explain.

In its 55-17 demolition of injury-riddled Arizona at Stanford Stadium on Saturday night, the No. 18 Cardinal looked nothing like the team that did little in its 16-6 loss to Northwestern.

Stanford (4-1, 3-0 Pac-12) has won four in a row since then and has shown improvement each week.

"We had our one game where we didn't play our best football," Stanford coach David Shaw.

Stanford running back Christian McCaffrey had his third straight 100-yard rushing game, running for 156 yards, 113 of which came in the first half. He also had a 67-yard kickoff return in the third quarter that led to a touchdown.

Quarterback Kevin Hogan completed 17 of 19 passes for 217 yards, two touchdowns and no interceptions. In Stanford's three Pac-12 games, Hogan is 44-for-56 (78.6 percent) with six touchdowns and one pick.

"I can't say enough about our quarterback and the leadership he's given us," Shaw said. "He's playing his best football."

The Cardinal racked up a season-high 570 yards of offense against the Wildcats and have scored more than 40 points in all three conference games.

Hogan, who is still bothered by an ankle injury, said he "absolutely" knew the Cardinal could be this productive, even after the egg they laid against Northwestern.

"We knew how good we could be coming out of training camp," he said. "It was just about executing."

Arizona was without starting quarterback Anu Solomon, who did not make the trip after suffering a concussion last week against UCLA, and the Wildcats were also missing several defensive starters.

Jerrard Randall started at quarterback for Arizona and completed 15 of 28 passes for 178 yards and a touchdown while running for 67 yards.

Arizona running back Nick Wilson, who led the Pac-12 in rushing with an average of 142.5 yards per game entering Saturday, was limited to 46 yards on 17 carries.

Arizona (3-2, 0-2) came into the game leading the Pac-12 in scoring, total offense and rushing. But the Wildcats were obviously hobbled by the absence of Solomon.

Wildcats coach Rich Rodriguez acknowledged that being without Solomon made the game a bigger challenge.

"Yeah, somewhat," he said. "I'm sure we're undersized, certainly, and that wasn't a good matchup. But that's an excuse. We didn't stop anything they wanted to do. They wanted to throw, they threw. They wanted to run, they ran."

It was the second straight one-sided loss for the Wildcats, who beat three overmatched opponents before losing to UCLA 56-30 last week.

The Cardinal held a commanding 27-3 lead at halftime and the Wildcats never recovered.

"We didn't play up to our intensity level," Wildcats wide receiver Johnny Jackson said. "We were facing adversity early and felt like we didn't play as hard as we could. That's just something we need to bounce back and get right next week."

Stanford jumped ahead 6-0 after Conrad Ukropina kicked field goals of 38 and 41 yards on the Cardinal's first two possessions.

Stanford increased its lead to 13-0 with 48 seconds left in the first quarter when McCaffrey completed a 63-yard drive with a 4-yard touchdown run -- his first rushing touchdown of the season.

Arizona then put together a 20-play, 73-yard drive that consumed 7:03 on the clock. But the Wildcats only got three points out of it as Casey Skowron kicked a 26-yard field goal to make it 13-3.

Stanford made it 20-3 on running back Remound Wright's 1-yard run. The touchdown was set up by McCaffrey's 25-yard run with backup quarterback Keller Chryst clearing the way for McCaffrey with a bruising block.

The Cardinal scored another touchdown on Hogan's 16-yard pass to Wright to increase the margin to 27-3 late in the second quarter.

Stanford does not play again until it hosts UCLA in a Thursday night game on Oct. 15. Shaw said he welcomes the break, mostly to get Hogan's ankle fully healed.

"What we're not seeing is his ability to be a threat as a runner," Shaw said. "Hopefully, he'll be healthy in 10 days."

NOTES: Arizona LB Scooby Wright, the Pac-12 defensive player of the year last season, did not play because of a foot injury suffered last week against UCLA. He is expected to miss a few more games. ... Wildcats QB Anu Solomon (concussion) was listed as a game-day decision during the week, but he did not even make the trip to Stanford. ... Stanford LB Kevin Anderson missed his second straight game with an undisclosed injury. ... Stanford QB Kevin Hogan did not put in a full week of practice because of a sprained ankle suffered two weeks ago, but he was in the starting lineup Saturday and did not seem to be limited. ... Entering this weekend, home teams were 0-6 in Pac-12 Conference games.