SAN FRANCISCO -- The 49ers' first-team offense -- or something along those lines -- made long work out of its only drive Friday night.Quarterback Alex Smith took 12 snaps in the 49ers' exhibition opener on Friday night at Candlestick Park, capping his night's work with a four-yard touchdown pass to Brett Swain.Smith completed all three of his pass attempts for 16 yards. He hit Michael Crabtree on a 3-yard pass, and he hit Kendall Hunter on a dump-off pass that gained 9 yards.Running back Frank Gore suited up and went through warmups. But he did not play in the game. Hunter got the start and picked up 22 yards on four rushing attempts.Veteran pickup Brandon Jacobs had a good first outing. He picked up three yards on a fourth-and-1 play from the 49ers' 47-yard line. He followed that up two plays later with a 23-yard run to the Vikings' 18-yard line.Randy Moss entered at wideout three plays into the game. He played four snaps but did not see any action come his way. Crabtree started and played five snaps. It was the first time Crabtree has seen action in an exhibition game since being drafted No. 10 overall by the 49ers in 2009.Smith's touchdown pass to Swain gave the 49ers a 7-3 lead with 5:13 remaining in the first quarter. Rock Cartwright had a big play with a 19-yard run for the 49ers on the team's second offensive play.