Jimmy Garoppolo's 5-yard touchdown pass to Dante Pettis with 1:15 left boosted the error-prone San Francisco 49ers to a 3-0 start as they rallied past the winless Pittsburgh Steelers 24-20 on Sunday in Santa Clara, Calif.

The score came seven plays after San Francisco's DeForest Buckner recovered Pittsburgh's James Conner's fumble at the Steelers' 24. Pittsburgh appeared to have stopped the 49ers and forced a field-goal attempt, but was flagged for defensive holding at the two-minute warning.

Two plays later, Garoppolo threw the game-winner, enabling him to offset a mistake-filled effort. He completed 23 of 32 passes for 277 yards with two interceptions. San Francisco won despite making five turnovers and committing 71 yards worth of penalties.

Steelers quarterback Mason Rudolph hit on 14 of 27 passes for 174 yards and two touchdowns, including a 39-yarder to rookie Diontae Johnson with 10:22 left in the game for a 20-17 edge. But Pittsburgh was outgained 436-239 on the day.

Coming off road wins over Tampa Bay and Cincinnati to start the year, San Francisco put itself into an immediate problem via sloppy play. Garoppolo threw an interception on his second pass to T.J. Watt, teeing up Chris Boswell for a 46-yard field goal just 3:13 into the game.

New Pittsburgh defensive back Minkah Fitzpatrick set up another score when he pilfered a Garoppolo throw late in the first quarter. Boswell cashed it in with a 26-yard field goal at the 2:04 mark for a 6-0 Steelers advantage.

San Francisco finally got on the board with 6:45 left in the first half when Robbie Gould converted a 24-yard field goal. Even that score had a taint of failure, as the 49ers reached the Pittsburgh 11 before a holding call backed them up.

Rudolph's first serious mistake enabled San Francisco to take its first lead in the third quarter. He was picked by K'Waun Williams at the Steelers' 38, and Wilson turned it into a 1-yard touchdown run and a 10-6 lead at the 9:17 mark.

Rudolph hit JuJu Smith-Schuster for a 76-yard catch-and-run 3 1/2 minutes later to retake the lead, but Wilson's 4-yard run in the final minute of the quarter put the 49ers up 17-13 headed to the fourth.

--Field Level Media