SANTA CLARA San Francisco's defense has a little game of its own in practice each week: "Takeaway Thursday."
Force as many turnovers as possible to prepare for more of the same Sunday. Linebacker NaVorro Bowman claims his unit had nine turnovers during one session recently though quarterback Alex Smith begs to differ, calling that number inflated. The total hardly matters. It's the principle.
"We go out and try to make as few mistakes as we possibly can," Bowman said. "We work on it every single day. We see where we end up and go into the game with that type of mindset."
Coach Jim Harbaugh isn't keeping track of turnovers in practice, though he loves the intense competition by his players leading up to games. And he's certainly thrilled that his defense delivered again with an interception and forced the New York Jets into three lost fumbles in Sunday's 34-0 win at the Meadowlands.
"It's the practice of the fundamentals of recovering footballs, diving on mistakes, clubbing, ripping, jarring the ball loose," Harbaugh said Monday of the preparation. "They treat each other with a great amount of respect, which I've always admired about our team. They enjoy the competition. It's competitive but not self-centered."
The dominant performance by defensive coordinator Vic Fangio's crew kept the Jets out of the red zone all day and further established the 49ers (3-1) as one of the NFL's elite teams even after that blip at Minnesota in a 24-13 Week 3 loss.
Harbaugh said the 49ers had prepared for Tim Tebow's signature jump pass even though New York had yet to run it, so San Francisco had no film of the play.
In New York's first drive of the second quarter, Tebow completed a nine-yard pass to Dedrick Epps. Safety Dashon Goldson forced a fumble, then recovered it.
It was the first turnover of three in a four-series stretch by the Jets.
The Buffalo Bills will try to clean things up in a hurry to avoid another ugly loss Sunday when they visit Candlestick Park. They committed six turnovers and blew a 14-point third-quarter lead in losing 52-28 at home Sunday to the New England Patriots.
Harbaugh's defense will be ready to pounce on any error.
"That was a gem our defense turned in," Harbaugh said, back in the Bay Area for the first time in more than a week after practicing in eastern Ohio ahead of Sunday's game. "Every guy played within the framework of the defense."
Mark Sanchez threw an interception and lost a fumble. He was sacked by Aldon Smith late in the first half and fumbled, with Justin Smith recovering.
That play gave the 49ers another chance before halftime, and David Akers kicked a 36-yard field goal to make it 10-0.
New York's longest drive was 30 yards to open the game and it ended in a punt. Sanchez finished his disappointing day 13 for 29 for 103 yards and an interception with three sacks and a dismal 39.9 quarterback rating.
"Defensively, we knew how we came and played last week," said cornerback Carlos Rogers, who recovered two fumbles and returned one for a touchdown.
"Coach Vic talked (last) week and told us to play 49ers ball and play how we should play. Did we imagine a shutout? No, but we finished plays, got turnovers and got off the field (after) third down."
The 49ers made keeping their defense together a top priority during the offseason. All 11 starters from last season's 13-3 team returned, though linebacker Parys Haralson was lost for the season early last month with a torn left triceps muscle.