When a Power 5 team is a two-touchdown favorite at home against a non-Power 5 team that lost its star player to the NFL, it might be a tad confident about its prospects.

Not Stanford.

The No. 13 Cardinal open their season Friday night against San Diego State, and they remember two shocking things that happened in the final minutes of last year’s game at San Diego Stadium.

First, the stadium lights went out, causing a 25-minute delay. Second, the Aztecs scored the decisive touchdown in a 20-17 win six plays after the lights returned on Christian Chapman’s 8-yard pass to tight end David Wells with 54 seconds left.

At game’s end, San Diego State fans rushed the field to celebrate the school’s first win over a ranked Power 5 team in 36 years.

When Stanford head coach David Shaw said this week, “We’re going to hope that doesn’t happen this year,” he was talking about the power failure. He obviously could have said the same thing about the game’s outcome.

That win was no fluke. San Diego State (10-3) had beaten another Pac-12 team, Arizona State, the previous week. Tailback Rashaad Penny had 175 yards on 35 carries against Stanford on his way to a nation’s-best 2,248-yard season and a first-round draft selection by Seattle.

“We got outplayed by them last year,” Shaw said. “They brought the fight to us, as opposed to the other way around.”

The Cardinal will start relatively inexperienced Michael Williams and Jovan Swann in their defensive line, and they’ll be on the spot against a team that, like Stanford, loves the ground game.

“These guys are going to run the ball down our throats if we’re not where we need to be,” Shaw said.

Penny replaced Donnel Pumphrey, who had led the nation with 2,133 yards rushing in 2016. San Diego State is the first school in history with back-to-back 2,000-yard seasons by different backs.

Now it’s Juwan Washington’s turn. A 5-foot-7, 190-pound Texan, Washington is said to be as elusive as Pumphrey, who’s 5-8, 170. Although smaller than Penny (5-11, 220), Washington can pack a wallop.

The redshirt junior carried 127 times for 759 yards and seven touchdowns last season, not bad for a backup. Like Penny, he returned two kickoffs for touchdowns last year. He’s “an explosive son of a gun,” Shaw said.

Clearly, the Aztecs’ Rocky Long is Shaw’s kind of head coach. “It’s football for tough guys,” Shaw said. “It’s football for smart guys. They stick to who they are, and they’ve been successful.”

The Aztecs have won three Mountain West Conference titles in Long’s seven seasons at the school. “Why they’re not ranked higher, I have no idea,” Shaw said.

Chapman stands an unimposing 6 feet tall, but he’s accurate, efficient and — as the Cardinal found out — capable of extending plays with his feet. He’s 23-6 as the starter, and one more win would give him the most of any quarterback in school history.

Shaw calls him one of the most underrated quarterbacks on the West Coast.

“He’s slippery,” he said. “Nobody talks about his athleticism. This guy gets out of danger. He pushes up in the pocket. He breaks tackles. He made some great throws in crunch-time situations against us, big-time college football throws. He’s their field general; he’s their leader.”

Last year’s game brought an intriguing matchup of the Holder twins, Stanford cornerback Alijah and San Diego State wide receiver Mikah. Mikah had the upper hand in the game and finished the season with 43 of the 78 catches by the Aztecs’ wide receivers.

He graduated, and Alijah won’t be back for the rematch, either. He’s nursing an injury.

Tom FitzGerald is a San Francisco Chronicle staff writer. Email: tfitzgerald@sfchronicle.com Twitter: @tomgfitzgerald