Inaugural nightmare at Levi's Stadium, as 49ers crushed by Broncos 34-0 (w/video)

SANTA CLARA - On a glorious sunny day, in the newest facility in professional sports, the 49ers played a game worthy of the most dismal recesses of Candlestick Park.

Outperformed in every phase of the game, Jim Harbaugh’s team christened Levi’s Stadium with a 34-0 preseason drubbing at the hands of the visiting Denver Broncos. The 49ers made one final attempt to crack the scoreboard in the closing moments, but running back Jewel Hampton was stuffed on fourth-and-goal from the 1-yard line with 15 seconds left, handing San Francisco its first preseason shutout since 1990, and its first at home since 1977.

“I didn’t think we executed well enough in any area today,” Harbaugh said afterward, in the spacious “auditorium” that has replaced Candlestick’s cramped interview room. “. . . We’ve gotta get better. This is gonna be an important week for us.”

The 49ers look like a shell of the team that made it to the NFC championship game last year, having lost 23-3 at Baltimore in the first exhibition game. The question is whether you can draw any inferences from a couple of preseason games. Even running back Frank Gore, the Niners’ resident mystic, seemed torn on the question.

Asked whether he gets concerned about poor results in August, Gore replied: “You can’t really, because it really . . . ”

Then he caught himself.

“Well,” Gore continued, “it depends what you look at. We haven’t scored a touchdown last two games. You look at that, that’s a negative. But it’s a positive that the starters are not really out there. Three plays here, three plays there. You’re not gonna look as you should look as a team. But when we’re practicing we look fine. We know what each guy can do once the season starts.”

To be fair to the 49ers, Gore - the 49ers’ workhorse for close to a decade - carried the ball just twice. Starting quarterback Colin Kaepernick, wide receivers Michael Crabtree and Anquan Boldin and tight end Vernon Davis were on the field for a couple possessions. The defense was without stalwarts like linebacker Patrick Willis, defensive lineman Justin Smith, defensive end Ray McDonald, cornerback Tramaine Brock and linebacker NaVorro Bowman, who is expected to miss half the regular season with a knee injury. The offensive line was missing right tackle Anthony Davis.

So yes, maybe the proper grade for the 49ers in this game would be an “incomplete.” That would be generous, because it would be hard to give them a letter grade higher than an F.

Broncos quarterback Peyton Manning was at his manic, cerebral best piloting the fast-paced Denver offense. He completed 12 of 14 passes for 102 yards and led the Broncos to a 10-0 lead, hitting tight end Julius Thomas with a 17-yard touchdown pass behind frustrated-looking safety Craig Dahl.

Then Manning headed to the sidelines - and the Broncos’ offensive attack barely skipped a beat. Second-teamer Brock Osweiler was 10 of 13 for 105 yards and a touchdown. Third-teamer Zac Dysert was 8 of 11 for 63 yards and a touchdown. All three combined for a passer rating of 122.6. They were rarely touched, and their receivers found plenty of open turf against the San Francisco secondary.

Kaepernick just missed wide receiver Brandon Lloyd on a deep pass into the end zone - it looked like Lloyd failed to adjust to the ball in flight - and otherwise didn’t accomplish much of anything. He finished 5 of 9 for 39 yards and left after two possessions.

But Kaepernick has proven himself capable of leading a team to the playoffs. He had the 49ers in the Super Bowl two years ago, and in the conference title game last year.

Much more distressing to Niners fans is the play of No. 2 quarterback Blaine Gabbert, who continues to struggle during the preseason, almost as badly as he struggled in Jacksonville last season. Gabbert failed to spot open receivers, and his one potentially productive deep pass, to Quinton Patton, was intercepted by Tony Carter.

“I’ve gotta get it up and over that nickel defender, and let Quinton make a play on the ball,” Gabbert said.

The only silver lining for Gabbert was that his competitors for the backup job, Josh Johnson and McLeod Bethel-Thompson, each turned over the ball as well, Johnson on a fumble (after he tripped on his center’s foot) and Bethel-Thompson on an interception.

But that is little consolation to 49ers fans who are getting increasingly worried about the prospect of an injury to Kaepernick.

The defense should get a boost next week. Harbaugh suggested veterans such as Smith, Willis and McDonald will make appearances here against the San Diego Chargers, which would give a better indication of where this team stands. Unfortunately, starting strong safety Antoine Bethea left the game early in the second quarter with a concussion.

Levi’s Stadium fared much better than its flagship team. The turf seemed a little loose in the vertical center of the field, and some players said they lost their footing a couple times. But the weather could scarcely have been more pleasant, and most of the traffic horrors reported from an MLS soccer game played here Aug. 2 seemed to have been smoothed over. The scoreboard graphics were crystal clear. The open concourse looked inviting, with fans milling about.

“It was awesome - a lot better than Candlestick,” free safety Eric Reid said.

If the 49ers can refurbish their play, they may really have something going here this season.