Nick Mullens got several hundred congratulatory text messages, a phone call from Brett Favre and his Twitter account verified.

Delivering the most productive game by a quarterback in his NFL debut since the merger leads to many accolades.

Mullens threw for 262 yards and three touchdowns and the San Francisco 49ers thoroughly dominated the Battle of the Bay, beating the Oakland Raiders 34-3 on Thursday night.

The former undrafted free agent out of Favre's alma mater Southern Mississippi finished 16-for-22 in place of the injured C.J. Beathard and had a 151.9 passer rating, the highest for a quarterback with at least 15 attempts in an NFL debut since the 1970 merger.

"I think I'm here for a reason. This is my opportunity to prove that I can play," Mullens said.

"Today's thing was just attack your job and worry about what matters. What mattered most tonight was the team and how we played."

The Niners (2-7) couldn't have played much better in stopping a six-game losing streak and winning for just the second time in two years without Jimmy Garoppolo at quarterback.

Mullens threw TD passes to Pierre Garcon and Kendrick Bourne on the opening two drives and connected on a 71-yard one-handed catch-and-run play to George Kittle to set up a third touchdown pass to Kittle.

Raheem Mostert added a 52-yard TD run and the defense generated eight sacks for the first time since 2009.

But the story of the game was Mullens, who got rid of the ball quickly and took advantages of several breakdowns in coverage for big plays, including the 24-yard TD pass to a wide-open Garcon on the opening drive.

"It was cool that he didn't change under the big lights and these circumstances," cornerback Richard Sherman said. "We're not really surprised. We've seen him do it in practice. He plays with a lot of confidence."

With Garoppolo out for the season and Beathard having lost nine of 10 career starts, the inevitable question will be whether Mullens will take over as starter for the next game Nov. 12 against the New York Giants.

"We'll definitely consider it," coach Kyle Shanahan said. "I'm definitely not thinking about it right now. Our whole team played very well. They definitely did."

The Raiders (1-7) clearly didn't, losing for the fourth straight time, getting outscored by 85 points during the skid.