1. Zimmer has last laugh on blitzing Garoppolo

No, Jimmy "7-1" Garoppolo won't win every NFL start. And Sunday's 24-16 loss to the Vikings also proved he isn't infallible against the blitz. In 14 first-half dropbacks, Garoppolo was blitzed only twice. He completed passes to convert on third-and-7 and third-and-6. A year ago, he led the league in completion percentage (68.1) when blitzed. "It's a catch-22, some," Vikings coach Mike Zimmer said of blitzing Garoppolo. Zimmer's third blitz was a home run. Sending linebacker Eric Kendricks and defensive back Jayron Kearse caused Garoppolo to throw a pick-six to Mike Hughes. Zimmer blitzed only three times through three quarters but turned it loose in the fourth quarter, leading to Xavier Rhodes' interception and Harrison Smith's sack.

2. Cousins' arm, poise show in red zone

A knock on Kirk Cousins coming from Washington was his red-zone efficiency. The Redskins ranked 17th in red-zone touchdown percentage last year (54.3) and 29th the year before (45.9). In his first red-zone trip as a Viking, Cousins went 2-for-2 with a first down and an 11-yard touchdown to Kyle Rudolph. Both throws were into tight coverage. The first completion — a 9-yarder to tight end David Morgan on third-and-1 — was a busted play. "I was supposed to block [Solomon Thomas], and we were going to throw to the fullback in the flat," Morgan said. "But [Thomas] slanted outside, so the play got busted right away. … So I gave Kirk my eyes, and he trusted me and threw a great ball into a tight window." The Vikings ran out the clock in their other red-zone trip.

3. Jones does OK vs. bland 49ers front

Fourteen days after being traded to the Vikings, Brett Jones started at center as Pat Elflein continues to recover from offseason surgeries. "I was actually pretty comfortable out there," he said. "I think I did OK." Not great, but OK. Unofficially, he gave up at least two pressures and was responsible for one false start. Surprisingly, the 49ers didn't do anything creative to try to confuse the interior of a line that hadn't played a snap together. Jones mostly matched up against Earl Mitchell, D.J. Jones or Arik Armstead. Mitchell and Jones are big, stationary bodies. The quicker Armstead got his pressure against Jones. "We got to get better on the line," Zimmer said. "But for a center to come in 10 days ago and start, I thought it was pretty impressive."

4. Vikings' first-down defense still needs work

49ers coach Kyle Shanahan does a nice job of confusing defenses on first downs. A year ago, the 49ers ranked fifth in the league in average gain on first down (6.01). Sunday, San Francisco averaged 6.5 yards on 31 first-down plays. The 49ers gained 202 of their 327 yards on first down. Garoppolo completed seven of 12 passes for 145 yards, including a couple of terribly busted coverages that resulted in a 56-yard wheel route to the fullback and a 36-yarder to the tight end. But the Vikings did counter with two sacks and Rhodes' fourth-quarter interception on first down. On third down, where the Vikings set a record (25.2 percent) a year ago, San Francisco converted just five of 13 attempts (38 percent).

5. A Mental Mistake of the Year contender

Yes, it's Week 1. But there's a good chance no NFL player will commit a mental mistake more avoidable than the one 49ers defensive end Solomon Thomas made with the Vikings leading 24-16 and facing fourth-and-1 at their 41 with 2:54 left. With the play clock almost at zero and Cousins about to give up on trying to get a defender to bite on the hard count, Thomas inexplicably jumped. "I've never seen it work in that situation," said Vikings left tackle Riley Reiff. "We practice it quite a bit. This time it worked, I guess." Thomas' blunder was one of only three 49ers penalties for 21 yards. But the blunder from last year's third overall draft pick enabled the Vikings to run an extra 1:05 off the clock before a punt pinned the 49ers at their 11.