Chicago, IL -- (Sports Network) - J.T. O'Sullivan completed 7-of-8 passes for 126 yards and a touchdown as San Francisco outgunned Chicago, 37-30, in preseason action from Soldier Field.

Jason Hill caught four balls for 94 yards and a score for the Niners (2-1). Dominique Zeigler also had a TD catch while Thomas Clayton rushed for 81 yards and a touchdown on 18 carries.

Alex Smith struggled under center for San Francisco, throwing for just 83 yards and one TD on 6-of-17 passing.

Kyle Orton, named the starting signal-caller earlier in the week, completed 10-of-17 passes for 147 yards and two touchdowns for the Bears (0-3). Rashied Davis was on the receiving end of both throws, hauling in four balls for 58 yards.

Zeigler's 12-yard catch for a score put the Niners ahead, 27-20, early in the third quarter. Robbie Gould booted a 28-yard field goal just under four minutes later to draw the Bears within four.

San Francisco then went up by 10 in the fourth on Clayton's 15-yard run and Ricky Schmitt's 31-yard make.

Brandon Rideau's leaping 51-yard touchdown reception from backup Caleb Hanie as time expired accounted for the final score.

The first half featured displays of offense on both sides.

Joe Nedney's 28-yard field goal capped off a successful opening drive for the visitors, but the Bears countered on Davis' 21-yard scoring catch from Orton.

Nedney drilled a 24-yarder before Gould made one from 21 yards out for a 10-6 Chicago lead.

O'Sullivan's 37-yard strike to Hill and a one-yard run by Moran Norris put the 49ers up 20 before the Bears closed out the half on Orton's seven-yard TD pass to Davis and Gould's hit from 24 yards out.