SANTA CLARA, Calif. (AP) — San Francisco’s rookie class made a positive first impression.

Led by first-round defensive standouts Solomon Thomas and Reuben Foster, the 49ers had to be pleased with what they saw from a strong draft class and a few undrafted free agents in a 27-17 exhibition opener victory over the Kansas City Chiefs on Friday night.

“I was excited for a lot of those guys,” coach Kyle Shanahan said Saturday. “That’s really what this preseason is for. You want to see it in the first game. You never play your starting guys very long. I thought our backups stepped in and did a good job.”

After matching a franchise-low with just two wins last season, the 49ers are starting a major rebuilding project under Shanahan and new general manager John Lynch.

Key to that process will be the performance of the team’s top two picks in April. Thomas, picked third overall, looked like he did when he dominated the defensive line in college at Stanford.

He applied the pressure that led to an early interception by Rashard Robinson, added a second pressure, a quarterback hit and made two tackles in the run game.

Foster, picked 31st, broke up a pass in the end zone and teamed with NaVorro Bowman to tackle Spencer Ware short of the end zone. Foster, who had no interceptions in high school or college, has had several so far on the practice field and was upset that he missed the one in the end zone against Alex Smith.

“I think I had something to prove,” Foster said. “A lot of guys were teasing me about the pass breakup. I could have caught a pick. They were talking about I caught all the picks in practice and I can’t catch one in the game, when the lights come on.”

Thomas…