CINCINNATI -- Quarterback Alex Smith saved his best for the last quarter on Sunday.After the offense muddled through an ineffective three quarters, the 49ers scored 10 fourth-quarter points in a 13-8 victory over the Cincinnati Bengals on Sunday at Paul Brown Stadium.Smith completed 5 of 6 passes for 57 yards in the final quarter. He finished the game with a season-best 201 yards on 20-of-30 passing. Smith did not throw an interception, while Bengals rookie quarterback Andy Dalton threw two fourth-quarter picks."I thought Alex played extremely well," 49ers coach Jim Harbaugh said. "He really managed the game well."The 49ers put together a 10-play, 72-yard touchdown drive on their possession after the Bengals took a 6-3 lead. Cincinnati was given its scoring chance after Frank Gore's fumble at the 49ers' 16-yard line."To become the type of team that wins on the road, you need to have poise," Smith said. "The defense kept us in it all day, and special teams played well. Offensively, we have to play better. To come back and have that fourth-quarter drive says a lot.""I think guys were fired up and wanted the ball back after our lost fumble," Smith said. "I've been on teams where it's, 'Here we go again.' But it's not like that here."On the season, Smith has completed 68.9 percent of his attempts (51 of 74) for 504 yards with two touchdowns and one interception. His passer rating is 91.3.Smith did not miss any action after reporting concussion symptoms following the 49ers' loss to the Dallas Cowboys last week. It didn't take Smith long Sunday to absorb a big hit. In the first quarter, he kept on a naked bootleg and took a crushing blow from Bengals cornerback Nate Clements."I heard the crowd and watched the replay," said Smith said. "It looked pretty good, but I felt fine."Smith was also sacked officially five times for minus-25 yards. In the second half, the 49ers made a change to their offensive line. Adam Snyder took over at right guard for struggling Chilo Rachal.The 49ers have allowed 11 sacks in the past two games. So what needs to change?"Nothing needs to change," Harbaugh said. "What we need to do is improve. That's what we're going to do in every area on the football team. I'm pleased with our guys. I thought they really sucked it up today."I thought they played tough. I thought they battled. That's what you want your football team to do, especially in the fourth quarter."