Nick Bosa likes his new friends on the San Francisco 49ers defensive line.

Maliek Collins weighs in at 310 pounds, has a thick beard and a mischievous smile. Collins came to the 49ers after making 112 starts in eight seasons with the Cowboys, Raiders and Texans. He knows how to fill the middle.

Leonard Floyd is only 240 pounds, below average, but fast. Floyd came to the 49ers after starting 120 games in his eight seasons with the Bears, Rams, and Bills. He knows how to put pressure on the passer.

Given their debut in San Francisco on Monday night, Collins and Floyd will get along well with Bosa.

Forget Aaron Rodgers for a moment. The 49ers pulled off an impressive 32-19 win at Levi’s Stadium, largely because they kept the New York Jets’ running game under control.

The Jets managed just 68 yards on the ground, including just 31 in three quarters (by which point the game was essentially already decided). Collins did his part by clogging the line of scrimmage and capitalizing on a New York fumble in the first quarter to set up Jake Moody’s first field goal.

Floyd also did his part by sacking Rodgers early in the second quarter, forcing the Jets to punt. The 49ers then stormed down the field and scored the game-winning touchdown, taking the lead and never relinquishing it.

This explains why Bosa strolled into his postgame press conference in an unmistakably good mood. The 49ers not only won their season opener, but also unveiled a revamped defense – and as always, the equation starts at the line.

“Floyd is just a ball of energy and he can run,” Bosa said. “People think he’s a smaller, skinnier guy who can’t run, but he’s incredibly explosive and can run like we need him to. Of course he can put pressure on (the passer), he’s proven that throughout his career.”

“And Maliek is a beast in the running game. If he can keep that up all year, we’ll be in a good position.”

The 49ers started their season with unanswered questions on defense. They named a new, inexperienced defensive coordinator, Nick Sorensen. They played without Arik Armstead (salary cap violation), Dre Greenlaw (recovering from a torn Achilles tendon) and Talanoa Hufanga (close to returning from a torn ACL).

But the defense looked as fearsome as ever.

Rodgers led the Jets on an impressive first-half charge, a 12-play, 70-yard march to a touchdown. New York’s other possessions before halftime produced this meager performance: 7 yards (culminating in a punt), 2 yards (fumble), 0 yards (punt), 5 yards (punt), minus 1 yard (end of half).

The Jets tried hard to establish their running game with third-year running back Breece Hall, who once played at Iowa State alongside a quarterback named Brock Purdy. Hall carried the ball 10 times in the first half and gained just 25 yards.

This has been a key component of the 49ers’ success over the past few years. They finished third in the NFL in rushing defense last season, second in 2022, seventh in 2021, and seventh in 2020.

“That’s our main focus every year,” Bosa said. “When you make teams one-dimensional, it’s huge. That’s always our main focus, especially with our D-line scheme and the way we make our linebackers play.”

“We are very proud of it. Last year we were not as good as we needed to be. So we had to improve.”

Bosa was quiet on Monday night, recording two quarterback hits but no sacks. As usual, he also drew a lot of attention – at one point, a Jets offensive lineman grabbed Bosa in a bear hug/head lock to keep him away from Rodgers (somehow, no penalty was called).

The 49ers obviously expect opponents to focus on Bosa, which makes it all the more important that other defensive linemen have an impact.

The presence of linebacker Fred Warner doesn’t hurt either. Warner forced Hall to fumble on New York’s fourth play, setting the tone for a largely spirited defensive performance.

The Jets scored two touchdowns in the final 18-plus minutes of the game, one at 26-7 and the other at 32-13.

One interested observer: Patrick Willis, the Hall of Fame linebacker. Willis, who visited the 49ers’ locker room after the game, acknowledged that the defensive performance helped ease any concerns about the offseason changes.

“They lost some players to free agents and injuries, so there was some uncertainty,” Willis said. “But in the first game, you felt like they filled those gaps and played good defense.”

As always, head coach Kyle Shanahan and general manager John Lynch tried to bolster their defense by adding linemen. Last year they signed two-time Pro Bowl nominee Javon Hargrave, and this past offseason they added Collins and Floyd.

The (very) first results are encouraging.

Reach Ron Kroichick: [email protected]; Twitter: @ronkroichick