CHICAGO — After Kyle Shanahanpress conference on Sunday afternoon, the San Francisco 49ersThe head coach left the podium, descended a riser and attempted to re-enter the visitors’ locker room adjacent to Soldier Field.
The door was locked.
As communications director Corry Rush knocked on the door asking for help, Shanahan appeared to be contemplating a scenario in which he had to continue answering reporters’ questions about his team’s 19-10 loss, stuffed with mistakes, which had just happened in the season opener against the Bears.
“This,” Shanahan said, “is the worst place to get trapped.”
Shanahan escaped the interrogation room without incident. But his team couldn’t do the same on the waterlogged field because of what Shanahan called ‘dumb penalties’ and ‘dumb mistakes’ in a game that ended with the Bears. doing festive slides in a mini-monsoon.
The 49ers had two turnovers, including a fumble on the Chicago 12-yard line, allowed a sack that took them out of field goal reach and committed 12 penalties for 99 yards as they lost a lead by 10 points in the third quarter as the Bears ended their upset victory with 19 unanswered points in the final 20-plus minutes.
LB Dr. Greenlaw: He had a 15-yard facemask penalty, an unnecessary 15-yard roughness penalty and was badly beaten in coverage on an 18-yard TD pass to WR Equanimeous St. Brown.
WR Jauan Jennings: He had four catches for 62 yards, both team highs. His 44-yard reception in the third quarter lasted his entire career and set a field goal.
DT Javon Kinlaw: He had near pressure from QB Justin Fields on the Bears’ first offensive play, but was otherwise hard to locate. Kinlaw didn’t appear on the stat sheet and was sidelined briefly with an ankle injury.
-Eric Branch
“We always talk about doing well longer,” Shanahan said. “And I think today was the exact opposite of that.”
Indeed, the 49ers — one season removed from the NFC Championship Game — made a late-game impression of the Bears, a six-win team in 2021 with a rookie head coach and 11 rookies on its 46-man active roster.
“It’s hard enough to play against the opposing team,” left tackle Trent Williams said. “It’s even harder when you’re playing against yourself.”
The Bears, seven-point home underdogs, were outscored 331-204, averaged 3.6 yards per game, and their offense was ungainly for nearly 40 minutes. At halftime, they had zero points, 19 net passing yards, and quarterback Justin Fields had a 2.8 passer rating.
But they won by leaving in large part because the 49ers gave them a slew of packed opportunities while saving the worst for last.
“We committed suicide,” linebacker Fred Warner said. “Each of those drives, you can look back and see that we did something to help them get into the end zone.”
Warner is right. The Bears scored three consecutive touchdowns, and each drive had remarkable symmetry: The 49ers took a killer penalty and the Bears quickly capitalized.
First, with the 49ers leading 10-0, linebacker Dre Greenlaw was given a 15-yard mask penalty after running back David Montgomery was stopped for a 1-yard gain on the 3rd and 4th of the 34 of the Bears. Three plays later: Fields threw a 51-yard touchdown pass to wide receiver Dante Pettis.
“The timing of the penalties,” Shanahan said, “was really crucial.”
In the Bears’ next practice, cornerback Charvarius Ward was flagged for holding 3rd-and-9 of the Bears’ 39. Three plays later, the 3rd-and-1 of 42 for the 49ers, linebacker Azeez Al-Shaair was flagged for unnecessary roughness when he pierced Fields mid-slide. Three plays later: Fields threw an 18-yard touchdown pass to receiver Equanimeous St. Brown for a 13-10 lead.
The 49ers had two unnecessary roughness penalties when Fields slipped.
“It was a point of attention and we talked about it,” Warner said. “We knew what it was with Fields and him slipping. We have to be smarter.
Trailing 13-10, Lance threw an interception that set up a 21-yard touchdown. And Chicago’s score was set up by a defensive tackle, Javon Kinlaw’s holding penalty on a 5-yard run on 2nd-and-11 of the 49ers’ 12. One play later: Khalil Herbert had a 3-yard run that gave the Bears a 19-10 lead.
“We have to play better,” Shanahan said, “and do it well for a lot longer than we have today.”
None of this was pretty: The 49ers’ nightmarish end clouded their botched start, filled with missed opportunities.
On their first practice, wide receiver Deebo Samuel lost a fumble at the Bears 12-yard line on a 4-yard run, first down. During their second practice, the quarterback Trey Lance airfielded a potential 32-yard touchdown pass to tight end Tyler Kroft, who had slipped behind two defenders.
Practice ended two plays later when right tackle Mike McGlinchey cleared a six-yard sack on the Bears’ 3rd-and-7 of 29, forcing a punt.
“I dropped a stupid bag that put us out of reach,” McGlinchey said. “Those are dots right there.”
Several players noted that the Bears couldn’t have rallied had they been sidelined early.
“Anytime you let a team hang around,” Williams said, “it’ll never be this good.”
The ex-49er ignites the rally: “It can really take a game for a team to get back into the game,” said fullback Kyle Juszczyk.
It’s easy to determine which play Juszczyk was referring to: Fields’ 51-yard touchdown pass to a lone Pettis, a former 49ers throwout, who provided his first points and kicked off his comeback.
What happened? Fields escaped the middle pressure of defensive tackle Arik Armstead, broke away to his left and threw a cross pass to Pettis, who had no defender within 10 yards of him when he caught the ball at 30.
“Fields did a hell of a job of getting away from it,” Shanahan said. “He bought time. And the cover doesn’t last that long.
Yet why was Pettis’ closest defender at Arlington Heights?
“You can put anything on me,” Talanoa Hufanga said. “We just have big eyes.”
Run too much? : Lance’s first start of the season felt like his first of his rookie season: he ran a lot.
A year after becoming one of 11 QBs since 1950 to make 16 carries in a regular season game, Lance made 13 carries (for 54 yards) on Sunday. Last season, Lance said he felt good after his 16-car performance against the Cardinals, but sprained his knee.
“I feel good,” Lance said Sunday. “Physically, just a few scratches, honestly, on the pitch. I didn’t feel like I took any big hits.
Lance is unlikely to stay healthy if he maintains a similar workload. Shanahan said the conditions on the pitch factored into how he used Lance.
“I’m going to go back and watch the tape and ask him how he felt,” Shanahan said. “But it was that kind of game.”
Eric Branch covers the 49ers for The San Francisco Chronicle. E-mail: ebranch@sfchronicle.com Twitter: @Eric_Branch