The 1972 USC football team was honored on the field at the Coliseum on Saturday, a tribute to past glory from a program that’s trying to replicate that team’s air of invincibility while it continues to emerge from the darkness that descended during the late stages of Clay Helton’s coaching tenure.

Consensus national champions at 12-0, the 1972 Trojans were considered one of the greatest teams ever assembled and perhaps the best of coach John McKay’s many outstanding teams. But in each of the two seasons before they reached the summit, they were 6-4-1 and struggled in conference play in what was then the Pacific-8.

It takes time to learn how to maintain the intensity and consistency that separate elite teams from the wannabes. The process can be uneven. It’s imperfect, often with a gain in one area balanced by a bad trend or mistakes in other areas. There are tests in every game, some of them exams that teams ace and some that they’re fortunate to squeak past.

Under coach Lincoln Riley, the current Trojans are grasping the importance of effort and constant attention to detail in supplementing their talent. They’re most of the way toward finding the effective blend they’ll need to stay in the conversation for the College Football Playoff, a mission they advanced Saturday by producing enough brilliant moments to outweigh their few lapses in a 30-14 victory over the tricky Washington State Cougars.

“Really tough, hard-fought win,” Riley said. “We told the guys all week, ‘Circumstances don’t make or break you. It’s how you respond to them.’ It’s been a tough grind to start to build this, but we’re having a hell of a lot of fun.”

In starting 6-0 for the first time since the 2006 Trojans — who finished 11-2 and beat Michigan to win the Rose Bowl on Jan. 1, 2007 — the No. 6 Trojans were lucky and were good Saturday.

The good fortune: most notably, when two Cougars penalties nullified an apparent interception by Chau Smith-Wade in the third quarter, allowing USC to keep possession and soon after extend its lead to 24-14 on a 38-yard touchdown pass by Caleb Williams to Mario Williams.

The good performances: Wide receiver Mario Williams caught four passes for 82 yards and two touchdowns. Running back Travis Dye had 28 carries for 149 yards (both season highs) and one touchdown, that coming on a four-yard rush late in the second quarter that erased Washington State’s 14-10 lead and put the Trojans ahead for good. Tuli Tuipulotu was dominant, making three monstrous sacks and five tackles, four of them for a loss. The defense banded together when the Trojans needed it most. “We continually found a way,” Riley said. The special teams were solid too, including field-goal kicker Denis Lynch’s three-for-three performance.

Quarterback Caleb Williams was 15 for 29 for 188 yards and two touchdowns and was more in command than he was two weeks ago at Oregon State but not as good as he was in his 27-for-37, 348-yard, three-touchdown performance last week against Arizona State. He got the job done, and that’s what mattered.

There’s room for USC to improve just about everywhere, but it’s impressive for a team that hasn’t yet established its credentials or identity to match a season low in points allowed while padding its record to 6-0. The Trojans’ defense, though progressively more depleted by injuries, held Cougars quarterback Cameron Ward to 172 passing yards, well below the 289 he averaged over his first five games, and sacked him five times.

USC wide receiver Mario Williams rejoices after he made a 38-yard, first-quarter touchdown catch. He finished with four receptions for 82 yards and two touchdowns.

(Gina Ferazzi / Los Angeles Times)

The Cougars had scored 110 points in their previous three games, but the Trojans shut them out in the second half, another step forward. The team’s culture is strong too, Riley said, with individual issues kept to a minimum. “We continue to get better and lean on each other,” he said.

The game against the Cougars loomed as the beginning of the Trojans’ toughest stretch to date, but they weren’t intimidated by adversity Saturday. They played with more of the “edge” Riley said they’d lacked last week, and they erased Washington State’s 14-10 second-quarter lead with no signs of panic or nerves. USC will play at Utah next week, and although that matchup lost some of its shine when the Utes lost to UCLA on Saturday at the Rose Bowl, Rice-Eccles Stadium is a tough place for visitors. USC can’t let up.

The Trojans’ travel schedule is light after that, with a bye week on Oct. 22 and a trip to Arizona on Oct. 29, but they don’t leave California again for the rest of the regular season. It’s a long way off, but it’s fun to dream about the USC-UCLA game at the Rose Bowl on Nov. 19 being a meeting of unbeaten teams.

All five teams ranked ahead of USC won Saturday, with all but No. 1 Alabama — a four-point winner over Texas A&M — romping by at least three touchdowns. The Trojans probably will stay where they are, at No. 6. But they finally have a clear path upward and out of the darkness of defeat.

“We know more challenges are upcoming,” Riley said. “I just really love coaching this team.”

It’s easy to see why. Their collective journey has begun with great promise, but it’s far from over.