DETROIT (AP) — Nick Bosa was ready to kick back and relax while the San Francisco 49ers coasted to a season-opening victory.

The Detroit Lions made Bosa get back to work.

Dre Greenlaw returned an interception for a touchdown to help San Francisco score 17 points over two-plus minutes late in the first half, and the Niners barely held on for a 41-33 win over Detroit on Sunday.

“I took my tape off and everything,” Bosa recalled. “I was expecting to be done.”

That was not an unrealistic expectation when San Francisco led 38-10 early in the fourth.

In coach Dan Campbell’s debut, Detroit scored 23 points in three-plus minutes to pull within eight points. The Lions, though, came up short by turning the ball over on downs at the San Francisco 24 with 12 seconds left after getting the ball back on Deebo Samuel’s fumble on what could have been a clinching gain.

For most of the afternoon, the 49ers performed more like the Super Bowl-contending team they were two years ago than the 10-loss squad they had last season when injuries took a major toll.

“We got into a pretty good groove and we were rolling pretty good, but you want to finish better than that,” quarterback Jimmy Garoppolo said. “There was a relaxation on the sideline.

“At the end of the day, it’s a win and we’re happy with that.”

Meanwhile, it looked like the many changes the Lions made might be moot until the comeback provided some hope.

“We dug ourselves into a really big ditch early against a very good team,” Campbell said. “We were better in the second half, but that wasn’t good enough.”

San Francisco welcomed back Garoppolo and George Kittle on offense and Nick Bosa on defense after each missed much of last season with injuries.

Garoppolo, who helped San Francisco win the 2019 NFC championship, is 23-8 in the regular season since being acquired from New England.

Kittle had four receptions for 78 yards. Bosa had four tackles, including a drive-ending sack early in the fourth quarter.

Garoppolo, who lost a fumble on his first snap, was 17 of 25 for 314 yards. He threw a 79-yard touchdown pass to Samuel, who took advantage of cornerback Jeff Okudah falling. That gave the Niners a 28-point cushion midway through the third quarter. They needed it.

Samuel had nine catches for a career-high 189 yards and lost the fumble in the final moments at the Lions 30. Rookie Elijah Mitchell, filling in for injured Raheem Mostert, had a tiebreaking, 38-yard touchdown run early in the second quarter and finished with 104 yards rushing.

In his Detroit debut, Jared Goff was 38 of 57 for 338 three touchdowns and a costly interception. T.J. Hockenson had a career-high eight receptions for 97 yards and scored in the season-opening game for the third time in three years.

Goff, the former Los Angeles Rams quarterback acquired along with first-round draft picks for Matthew Stafford, was picked off late in the second quarter by Greenlaw. The linebacker returned the interception 39 yards to give San Francisco a 28-10 lead. The Niners led 31-10 at halftime, their highest total after two quarters since 2008.

Goff, and his teammates, bounced back enough to potentially push the game into overtime.

“The end of the game showed us what kind of guys we have on this team,” he said. “I learned a lot about them and I hope they learned a lot about me.”

INJURY REPORT

Lions: WR Kalif Raymond limped off the field, favoring his left leg in the third quarter. On a play in the fourth quarter, both Okudah (foot) and DT Kevin Strong were injured. Campbell said Okudah, the No. 3 pick overall last year, might have injured his Achilles tendon.

UP NEXT

Lions: at Green Bay on Sept. 20.