SANTA CLARA, Calif. -- Brandon Marshall walked up to Jay Cutler and planted a congratulatory kiss on his quarterback's head.

No doubt the admiration and appreciation -- relief, too -- went both ways. Down big, Cutler kept his poise on the road. Marshall relied on adrenaline to carry him on a bum ankle, cleared to play just 90 minutes before kickoff.

Cutler found Marshall for two of his three fourth-quarter touchdown passes after much of Chicago's starting defense went down, and the Bears beat the San Francisco 49ers 28-20 Sunday night to spoil their Levi's Stadium debut.

"The defense did a great job giving us short fields, causing turnovers and keeping it close enough so that we could get back in it," Cutler said.

Cutler and Marshall clicked as Chicago erased a late 13-point deficit and quieted the sellout crowd. Cutler threw for two scores in a 27-second span early in the final period, aided by the gutsy play of a backup cornerback.

Kyle Fuller made two late interceptions for the depleted Chicago secondary, and the first set up the go-ahead score.

"We all still had confidence, we knew we were going to pull it out," said Fuller, the Bears' first-round pick in this year's draft.

Kaepernick was hit with an unsportsmanlike conduct penalty for "inappropriate language" following Fuller's first big play. That gave the Bears first-and-goal on the 3, and Cutler threw a 3-yard TD pass to Martellus Bennett for a 21-20 lead.

Kaepernick threw three interceptions in all, lost a fumble and his cool, a far cry from his breakout start on the Monday night stage nearly two years ago in a rout of the Bears. Cutler sat out that night with a concussion.

"We hurt ourselves," Kaepernick said, insisting he didn't say anything wrong.

A sloppy game filled with 26 penalties -- 16 by the Niners -- and a crazy collapse overshadowed the fanfare of the regular-season debut for the sparkling $1.2 billion stadium.

The Bears (1-1), in a stretch with six of eight games on the road, go home with some serious momentum despite injuries on both sides of the ball. Cutler finished 23 of 34 for 176 yards and four TDs.